AI routines and Energy Trans logic

8 files changed, 1013 insertions, 212 deletions

diff --git a/src/constants/duel_constants.asm b/src/constants/duel_constants.asm
index 65f58e3..b667c50 100644
--- a/src/constants/duel_constants.asm
+++ b/src/constants/duel_constants.asm
@@ -232,21 +232,32 @@ AI_FLAG_USED_PROFESSOR_OAK EQU 1 << 2
 AI_FLAG_MODIFIED_HAND      EQU 1 << 3
 AI_FLAG_USED_GUST_OF_WIND  EQU 1 << 4
 
+; used as input for AIProcessEnergyCards to determine what to check
+; and whether to play card after the routine is over.
+; I suspect AI_ENERGY_FLAG_DONT_PLAY to be a flag to signal the routine
+; not to actually play the energy card after it's finished,
+; but AIProcessEnergyCards checks whether ANY flag is set in order
+; to decide not to play it, so it's redundant in the presence of another flag.
+AI_ENERGY_FLAG_DONT_PLAY       EQU 1 << 0 ; whether to play energy card (?)
+AI_ENERGY_FLAG_SKIP_EVOLUTION  EQU 1 << 1 ; whether to check if card has evolutions
+AI_ENERGY_FLAG_SKIP_ARENA_CARD EQU 1 << 7 ; whether to include Arena card in determining which card to attach energy
+
 ; used to determine which Trainer cards for AI
 ; to process in AIProcessHandTrainerCards.
 ; aside from a few exceptions, these go in chronological order.
-AI_TRAINER_CARD_PHASE_01 EQU $1
-AI_TRAINER_CARD_PHASE_02 EQU $2
-AI_TRAINER_CARD_PHASE_03 EQU $3
-AI_TRAINER_CARD_PHASE_04 EQU $4
-AI_TRAINER_CARD_PHASE_05 EQU $5
-AI_TRAINER_CARD_PHASE_06 EQU $6
-AI_TRAINER_CARD_PHASE_07 EQU $7
-AI_TRAINER_CARD_PHASE_08 EQU $8
-AI_TRAINER_CARD_PHASE_09 EQU $9
-AI_TRAINER_CARD_PHASE_10 EQU $a
-AI_TRAINER_CARD_PHASE_11 EQU $b
-AI_TRAINER_CARD_PHASE_12 EQU $c
-AI_TRAINER_CARD_PHASE_13 EQU $d
-AI_TRAINER_CARD_PHASE_14 EQU $e
-AI_TRAINER_CARD_PHASE_15 EQU $f
+	const_def 1
+	const AI_TRAINER_CARD_PHASE_01 ; $1
+	const AI_TRAINER_CARD_PHASE_02 ; $2
+	const AI_TRAINER_CARD_PHASE_03 ; $3
+	const AI_TRAINER_CARD_PHASE_04 ; $4
+	const AI_TRAINER_CARD_PHASE_05 ; $5
+	const AI_TRAINER_CARD_PHASE_06 ; $6
+	const AI_TRAINER_CARD_PHASE_07 ; $7
+	const AI_TRAINER_CARD_PHASE_08 ; $8
+	const AI_TRAINER_CARD_PHASE_09 ; $9
+	const AI_TRAINER_CARD_PHASE_10 ; $a
+	const AI_TRAINER_CARD_PHASE_11 ; $b
+	const AI_TRAINER_CARD_PHASE_12 ; $c
+	const AI_TRAINER_CARD_PHASE_13 ; $d
+	const AI_TRAINER_CARD_PHASE_14 ; $e
+	const AI_TRAINER_CARD_PHASE_15 ; $f
diff --git a/src/engine/bank01.asm b/src/engine/bank01.asm
index b73b47c..7668903 100644
--- a/src/engine/bank01.asm
+++ b/src/engine/bank01.asm
@@ -6835,6 +6835,7 @@ OppAction_ExecutePokemonPowerEffect: ; 6b07 (1:6b07)
 	ret
 ; 0x6b15
 
+; execute the EFFECTCMDTYPE_AFTER_DAMAGE command of the used Pokemon Power
 OppAction_6b15: ; 6b15 (1:6b15)
 	ld a, EFFECTCMDTYPE_AFTER_DAMAGE
 	call TryExecuteEffectCommandFunction
diff --git a/src/engine/bank05.asm b/src/engine/bank05.asm
index ee45de4..ba0a565 100644
--- a/src/engine/bank05.asm
+++ b/src/engine/bank05.asm
@@ -74,8 +74,8 @@ Func_14078: ; 14078 (5:4078)
 	call AIDecideBenchPokemonToSwitchTo
 	call AIChooseEnergyToDiscardForRetreatCost
 .asm_14091
-	call AIDecidePlayEnergyCardFromHand
-	call Func_169f8
+	call AIProcessAndTryToPlayEnergy
+	call AIProcessAndTryToUseAttack
 	ret c
 	ld a, OPPACTION_FINISH_NO_ATTACK
 	bank1call AIMakeDecision
@@ -220,8 +220,44 @@ LoadDefendingPokemonColorWRAndPrizeCards: ; 1411d (5:411d)
 	ret
 ; 0x14145
 
-Func_14145: ; 14145 (5:4145)
-	INCROM $14145, $14184
+; called when AI has chosen its attack.
+; executes all effects and damage.
+; handles AI choosing parameters for certain attacks as well.
+AITryUseAttack: ; 14145 (5:4145)
+	ld a, [wSelectedAttack]
+	ldh [hTemp_ffa0], a
+	ld e, a
+	ld a, DUELVARS_ARENA_CARD
+	call GetTurnDuelistVariable
+	ldh [hTempCardIndex_ff9f], a
+	ld d, a
+	call CopyMoveDataAndDamage_FromDeckIndex
+	ld a, OPPACTION_BEGIN_ATTACK
+	bank1call AIMakeDecision
+	ret c
+
+	call AISelectSpecialAttackParameters
+	jr c, .use_attack
+	ld a, OPPACTION_BEGIN_ATTACK
+	call TryExecuteEffectCommandFunction
+
+.use_attack
+	ld a, [wSelectedAttack]
+	ld e, a
+	ld a, DUELVARS_ARENA_CARD
+	call GetTurnDuelistVariable
+	ld d, a
+	call CopyMoveDataAndDamage_FromDeckIndex
+	ld a, OPPACTION_USE_ATTACK
+	bank1call AIMakeDecision
+	ret c
+
+	ld a, OPPACTION_ATTACK_ANIM_AND_DAMAGE
+	call TryExecuteEffectCommandFunction
+	ld a, OPPACTION_ATTACK_ANIM_AND_DAMAGE
+	bank1call AIMakeDecision
+	ret
+; 0x14184
 
 ; return carry if any of the following is satisfied:
 ;	- deck index in a corresponds to a double colorless energy card;
@@ -1145,7 +1181,7 @@ PointerTable_14668: ; 14668 (05:4668)
 	dw Func_14674 ; not used
 	dw Func_14674 ; general AI for battles
 	dw Func_14678 ; basic pokemon placement / cheater shuffling on better AI
-	dw Func_1467f
+	dw Func_1467f ; deciding which Bench Pokemon to switch to
 	dw Func_14683
 	dw Func_14687
 
@@ -1160,11 +1196,11 @@ Func_14678: ; 14678 (5:4678)
 	ret
 
 Func_1467f: ; 1467f (5:467f)
-	call $5b72
+	call AIDecideBenchPokemonToSwitchTo
 	ret
 
 Func_14683: ; 14683 (5:4683)
-	call $5b72
+	call AIDecideBenchPokemonToSwitchTo
 	ret
 
 Func_14687: ; 14687 (5:4687)
@@ -1174,105 +1210,108 @@ Func_14687: ; 14687 (5:4687)
 ; AI for general decks i think
 Func_1468b: ; 1468b (5:468b)
 	call Func_15649
-	ld a, $1
+
+	ld a, AI_TRAINER_CARD_PHASE_01
 	call AIProcessHandTrainerCards
-	farcall $8, $67d3
-	jp nc, $4776
-	farcall $8, $6790
-	farcall $8, $66a3
-	farcall $8, $637f
+	farcall Func_227d3
+	jp nc, .asm_14776
+
+	farcall Func_22790
+	farcall Func_226a3
+	farcall Func_2237f
 	ret c
-	farcall $8, $662d
-	ld a, $2
+
+	farcall Func_2262d
+
+	ld a, AI_TRAINER_CARD_PHASE_02
 	call AIProcessHandTrainerCards
-	ld a, $3
+	ld a, AI_TRAINER_CARD_PHASE_03
 	call AIProcessHandTrainerCards
-	ld a, $4
+	ld a, AI_TRAINER_CARD_PHASE_04
 	call AIProcessHandTrainerCards
-	call $5eae
+	call AIDecidePlayPokemonCard
 	ret c
-	ld a, $5
+
+	ld a, AI_TRAINER_CARD_PHASE_05
 	call AIProcessHandTrainerCards
-	ld a, $6
+	ld a, AI_TRAINER_CARD_PHASE_06
 	call AIProcessHandTrainerCards
-	ld a, $7
+	ld a, AI_TRAINER_CARD_PHASE_07
 	call AIProcessHandTrainerCards
-	ld a, $8
+	ld a, AI_TRAINER_CARD_PHASE_08
 	call AIProcessHandTrainerCards
-	call $4786
-	ld a, $a
+	call Func_14786
+	ld a, AI_TRAINER_CARD_PHASE_10
 	call AIProcessHandTrainerCards
-	ld a, $b
+	ld a, AI_TRAINER_CARD_PHASE_11
 	call AIProcessHandTrainerCards
-	ld a, $c
+	ld a, AI_TRAINER_CARD_PHASE_12
 	call AIProcessHandTrainerCards
 	ld a, [wAlreadyPlayedEnergy]
 	or a
 	jr nz, .asm_146ed
-	call $64e8
-
+	call AIProcessAndTryToPlayEnergy
 .asm_146ed
-	call $5eae
-	farcall $8, $66a3
-	farcall $8, $637f
+	call AIDecidePlayPokemonCard
+	farcall Func_226a3
+	farcall Func_2237f
 	ret c
-	farcall $8, $6790
-	ld a, $d
-	farcall $8, $619b
-	ld a, $d
+	farcall Func_22790
+	ld a, $0d
+	farcall HandleAIEnergyTrans
+	ld a, AI_TRAINER_CARD_PHASE_13
 	call AIProcessHandTrainerCards
-	ld a, $f
+	ld a, AI_TRAINER_CARD_PHASE_15
 	call AIProcessHandTrainerCards
 	ld a, [wPreviousAIFlags]
-	and AI_FLAG_USED_PROFESSOR_OAK
+	and $04
 	jr z, .asm_14776
-	ld a, $1
+	ld a, AI_TRAINER_CARD_PHASE_01
 	call AIProcessHandTrainerCards
-	ld a, $2
+	ld a, AI_TRAINER_CARD_PHASE_02
 	call AIProcessHandTrainerCards
-	ld a, $3
+	ld a, AI_TRAINER_CARD_PHASE_03
 	call AIProcessHandTrainerCards
-	ld a, $4
+	ld a, AI_TRAINER_CARD_PHASE_04
 	call AIProcessHandTrainerCards
-	call $5eae
+	call AIDecidePlayPokemonCard
 	ret c
-	ld a, $5
+	ld a, AI_TRAINER_CARD_PHASE_05
 	call AIProcessHandTrainerCards
-	ld a, $6
+	ld a, AI_TRAINER_CARD_PHASE_06
 	call AIProcessHandTrainerCards
-	ld a, $7
+	ld a, AI_TRAINER_CARD_PHASE_07
 	call AIProcessHandTrainerCards
-	ld a, $8
+	ld a, AI_TRAINER_CARD_PHASE_08
 	call AIProcessHandTrainerCards
-	call $4786
-	ld a, $a
+	call Func_14786
+	ld a, AI_TRAINER_CARD_PHASE_10
 	call AIProcessHandTrainerCards
-	ld a, $b
+	ld a, AI_TRAINER_CARD_PHASE_11
 	call AIProcessHandTrainerCards
-	ld a, $c
+	ld a, AI_TRAINER_CARD_PHASE_12
 	call AIProcessHandTrainerCards
 	ld a, [wAlreadyPlayedEnergy]
 	or a
 	jr nz, .asm_1475b
-	call $64e8
-
+	call AIProcessAndTryToPlayEnergy
 .asm_1475b
-	call $5eae
-	farcall $8, $66a3
-	farcall $8, $637f
+	call AIDecidePlayPokemonCard
+	farcall Func_226a3
+	farcall Func_2237f
 	ret c
-	farcall $8, $6790
-	ld a, $d
-	farcall $8, $619b
-	ld a, $d
+	farcall Func_22790
+	ld a, $0d
+	farcall HandleAIEnergyTrans
+	ld a, AI_TRAINER_CARD_PHASE_13
 	call AIProcessHandTrainerCards
 
 .asm_14776
-	ld a, $e
-	farcall $8, $619b
-	call $69f8
+	ld a, $0e
+	farcall HandleAIEnergyTrans
+	call AIProcessAndTryToUseAttack
 	ret c
-	ld a, $5
+	ld a, OPPACTION_FINISH_NO_ATTACK
 	bank1call AIMakeDecision
 	ret
 ; 0x14786
@@ -1735,6 +1774,8 @@ CountNumberOfEnergyCardsAttached: ; 15787 (5:5787)
 ; input:
 ;	a = card location to look in;
 ;	e = card ID to look for.
+; output:
+;	a = deck index of card found, if any
 CheckIfAnyCardIDinLocation: ; 157a3 (5:57a3)
 	ld b, a
 	ld c, e
@@ -2207,7 +2248,7 @@ AIDecideWhetherToRetreat: ; 158b2 (5:58b2)
 .one_or_none
 	call CheckIfArenaCardIsAtHalfHPCanEvolveAndUseSecondMove
 	jr c, .check_defending_can_ko
-	call CheckIfBenchCardsAreAtHalfHPCanEvolveAndUseSecondMove
+	call CountNumberOfSetUpBenchPokemon
 	cp 2
 	jr c, .check_defending_can_ko
 	call AddToAIScore
@@ -2324,7 +2365,8 @@ Func_15b54: ; 15b54 (5:5b54)
 
 ; calculates AI score for bench Pokémon
 ; returns in hTempPlayAreaLocation_ff9d the
-; Play Area location of best card to switch to
+; Play Area location of best card to switch to.
+; returns carry if no Bench Pokemon.
 AIDecideBenchPokemonToSwitchTo: ; 15b72 (5:5b72)
 	xor a
 	ldh [hTempPlayAreaLocation_ff9d], a
@@ -2376,17 +2418,17 @@ AIDecideBenchPokemonToSwitchTo: ; 15b72 (5:5b72)
 	xor a
 	ld [wSelectedAttack], a
 	call CheckIfSelectedMoveIsUnusable
-	call nc, .calculate_damage
+	call nc, .HandleAttackDamageScore
 	ld a, $01
 	ld [wSelectedAttack], a
 	call CheckIfSelectedMoveIsUnusable
-	call nc, .calculate_damage
+	call nc, .HandleAttackDamageScore
 	jr .check_energy_card
 
 ; adds to AI score depending on amount of damage
 ; it can inflict to the defending Pokémon
 ; AI score += floor(Damage / 10) + 1
-.calculate_damage
+.HandleAttackDamageScore
 	ld a, [wSelectedAttack]
 	call EstimateDamage_VersusDefendingCard
 	ld a, [wDamage]
@@ -4006,47 +4048,58 @@ CheckForEvolutionInDeck: ; 16451 (5:6451)
 Func_16488 ; 16488 (5:6488)
 	INCROM $16488, $164a1
 
-; copies wPlayAreaAIScore to wTempPlayAreaAIScore.
-; copies AIScore to wcde3.
-; decides which card to get energy card.
-Func_164a1: ; 164a1 (5:64a1)
-	ld a, $03
-	ld [wcdd8], a
+; have AI choose an energy card to play, but do not play it.
+; does not consider whether the cards have evolutions to be played.
+; return carry if an energy card is chosen to use in any Play Area card,
+; and if so, return its Play Area location in hTempPlayAreaLocation_ff9d.
+AIProcessButDontPlayEnergy_SkipEvolution: ; 164a1 (5:64a1)
+	ld a, AI_ENERGY_FLAG_DONT_PLAY | AI_ENERGY_FLAG_SKIP_EVOLUTION
+	ld [wAIEnergyAttachLogicFlags], a
+
+; backup wPlayAreaAIScore in wTempPlayAreaAIScore.
 	ld de, wTempPlayAreaAIScore
 	ld hl, wPlayAreaAIScore
 	ld b, MAX_PLAY_AREA_POKEMON
-.loop_play_area
+.loop
 	ld a, [hli]
 	ld [de], a
 	inc de
 	dec b
-	jr nz, .loop_play_area
+	jr nz, .loop
 
 	ld a, [wAIScore]
 	ld [de], a
-	jr AIDecideWhichCardToAttachEnergy
 
-Func_164ba: ; 164ba (5:64ba)
-	ld a, $83
-	ld [wcdd8], a
+	jr AIProcessEnergyCards
+
+; have AI choose an energy card to play, but do not play it.
+; does not consider whether the cards have evolutions to be played.
+; return carry if an energy card is chosen to use in any Bench card,
+; and if so, return its Play Area location in hTempPlayAreaLocation_ff9d.
+AIProcessButDontPlayEnergy_SkipEvolutionAndArena: ; 164ba (5:64ba)
+	ld a, AI_ENERGY_FLAG_DONT_PLAY | AI_ENERGY_FLAG_SKIP_EVOLUTION | AI_ENERGY_FLAG_SKIP_ARENA_CARD
+	ld [wAIEnergyAttachLogicFlags], a
+
+; backup wPlayAreaAIScore in wTempPlayAreaAIScore.
 	ld de, wTempPlayAreaAIScore
 	ld hl, wPlayAreaAIScore
 	ld b, MAX_PLAY_AREA_POKEMON
-.asm_164c7
+.loop
 	ld a, [hli]
 	ld [de], a
 	inc de
 	dec b
-	jr nz, .asm_164c7
+	jr nz, .loop
 
 	ld a, [wAIScore]
 	ld [de], a
-	jr AIDecideWhichCardToAttachEnergy
+
+	jr AIProcessEnergyCards
 
 ; copies wTempPlayAreaAIScore to wPlayAreaAIScore
-; and loads wAIscore with value in wcde3.
-; identical to Func_169e3.
-Func_164d3: ; 164d3 (5:64d3)
+; and loads wAIscore with value in wTempAIScore.
+; identical to RetrievePlayAreaAIScoreFromBackup2.
+RetrievePlayAreaAIScoreFromBackup1: ; 164d3 (5:64d3)
 	push af
 	ld de, wPlayAreaAIScore
 	ld hl, wTempPlayAreaAIScore
@@ -4065,34 +4118,37 @@ Func_164d3: ; 164d3 (5:64d3)
 
 ; have AI decide whether to play energy card from hand 
 ; and determine which card is best to attach it.
-AIDecidePlayEnergyCardFromHand: ; 164e8 (5:64e8)
+AIProcessAndTryToPlayEnergy: ; 164e8 (5:64e8)
 	xor a
-	ld [wcdd8], a
+	ld [wAIEnergyAttachLogicFlags], a
 	call CreateEnergyCardListFromHand
-	jr nc, AIDecideWhichCardToAttachEnergy
+	jr nc, AIProcessEnergyCards
 
 ; no energy
-	ld a, [wcdd8]
+	ld a, [wAIEnergyAttachLogicFlags]
 	or a
 	jr z, .exit
-	jp Func_164d3
+	jp RetrievePlayAreaAIScoreFromBackup1
 .exit
 	or a
 	ret
 
 ; have AI decide whether to play energy card
 ; and determine which card is best to attach it.
-AIDecideWhichCardToAttachEnergy: ; 164fc (5:64fc)
+AIProcessEnergyCards: ; 164fc (5:64fc)
+; initialize Play Area AI score
 	ld a, $80
 	ld b, MAX_PLAY_AREA_POKEMON
-	ld hl, wcde4
+	ld hl, wPlayAreaEnergyAIScore
 .loop
 	ld [hli], a
 	dec b
 	jr nz, .loop
 
+; Legendary Articuno Deck has its own energy card logic
 	call HandleLegendaryArticunoEnergyScoring
 
+; start the main Play Area loop
 	ld b, PLAY_AREA_ARENA
 	ld a, DUELVARS_NUMBER_OF_POKEMON_IN_PLAY_AREA
 	call GetTurnDuelistVariable
@@ -4106,8 +4162,8 @@ AIDecideWhichCardToAttachEnergy: ; 164fc (5:64fc)
 	ld [wAIScore], a
 	ld a, $ff
 	ld [wTempAI], a
-	ld a, [wcdd8]
-	and $02
+	ld a, [wAIEnergyAttachLogicFlags]
+	and AI_ENERGY_FLAG_SKIP_EVOLUTION
 	jr nz, .check_venusaur
 
 ; check if energy needed is found in hand
@@ -4125,7 +4181,7 @@ AIDecideWhichCardToAttachEnergy: ; 164fc (5:64fc)
 	ld a, [wCurCardCanAttack]
 	call CheckForEvolutionInList
 	jr nc, .no_evolution_in_hand
-	ld [wTempAI], a
+	ld [wTempAI], a ; store evolution card found
 	ld a, 2
 	call AddToAIScore
 	jr .check_venusaur
@@ -4137,8 +4193,9 @@ AIDecideWhichCardToAttachEnergy: ; 164fc (5:64fc)
 	ld a, 1
 	call AddToAIScore
 
-; if there's no Muk in Play Area
-; and there's Venusaur2, add to AI score
+; if there's no Muk in any Play Area
+; and there's Venusaur2 in own Play Area,
+; add to AI score
 .check_venusaur
 	ld a, MUK
 	call CountPokemonIDInBothPlayAreas
@@ -4157,27 +4214,27 @@ AIDecideWhichCardToAttachEnergy: ; 164fc (5:64fc)
 ; arena
 	ld a, [wcda7]
 	bit 7, a
-	jr z, .check_arena_hp
+	jr z, .skip_subtracting_score
 	ld a, 5
 	call SubFromAIScore
 	jr .check_defending_can_ko
 
-; lower AI score if poison/double poison
-; will KO Pokémon between turns
-; or if the defending Pokémon can KO
-.check_arena_hp
+.skip_subtracting_score
 	ld a, 4
 	call AddToAIScore
 
+; lower AI score if poison/double poison
+; will KO Pokémon between turns
+; or if the defending Pokémon can KO
 	ld a, DUELVARS_ARENA_CARD_HP
 	call GetTurnDuelistVariable
 	call CalculateByteTensDigit
 	cp 3
 	jr nc, .check_defending_can_ko
-; hp < 30
+	; hp < 30
 	cp 2
 	jr z, .has_20_hp
-; hp = 10
+	; hp = 10
 	ld a, DUELVARS_ARENA_CARD_STATUS
 	call GetTurnDuelistVariable
 	and POISONED
@@ -4288,11 +4345,12 @@ AIDecideWhichCardToAttachEnergy: ; 164fc (5:64fc)
 .check_boss_deck
 	call CheckIfNotABossDeckID
 	jr c, .skip_boss_deck
+
 	call Func_174f2
 	ldh a, [hTempPlayAreaLocation_ff9d]
 	ld c, a
 	ld b, $00
-	ld hl, wcde4
+	ld hl, wPlayAreaEnergyAIScore
 	add hl, bc
 	ld a, [hl]
 	cp $80
@@ -4336,24 +4394,24 @@ AIDecideWhichCardToAttachEnergy: ; 164fc (5:64fc)
 ; for each card has been calculated.
 ; now to determine the highest score.
 	call FindPlayAreaCardWithHighestAIScore
-	jp nc, .asm_1668a
+	jp nc, .not_found
 
-	ld a, [wcdd8]
+	ld a, [wAIEnergyAttachLogicFlags]
 	or a
 	jr z, .play_card
 	scf
-	jp Func_164d3
+	jp RetrievePlayAreaAIScoreFromBackup1
 
 .play_card
 	call CreateEnergyCardListFromHand
 	jp AITryToPlayEnergyCard
 
-.asm_1668a: ; 1668a (5:668a)
-	ld a, [wcdd8]
+.not_found: ; 1668a (5:668a)
+	ld a, [wAIEnergyAttachLogicFlags]
 	or a
-	jr z, .asm_16693
-	jp Func_164d3
-.asm_16693
+	jr z, .no_carry
+	jp RetrievePlayAreaAIScoreFromBackup1
+.no_carry
 	or a
 	ret
 ; 0x16695
@@ -4562,15 +4620,17 @@ DetermineAIScoreOfMoveEnergyRequirement: ; 16695 (5:6695)
 ; of the card with the highest Play Area AI score, unless
 ; the highest score is below $85.
 ; if it succeeds in return a card location, set carry.
+; if AI_ENERGY_FLAG_SKIP_ARENA_CARD is set in wAIEnergyAttachLogicFlags
+; doesn't include the Arena card and there's no minimum score.
 FindPlayAreaCardWithHighestAIScore: ; 167b5 (5:67b5)
-	ld a, [wcdd8]
-	and $80
-	jr nz, .asm_167e1
+	ld a, [wAIEnergyAttachLogicFlags]
+	and AI_ENERGY_FLAG_SKIP_ARENA_CARD
+	jr nz, .only_bench
 
 	ld a, DUELVARS_NUMBER_OF_POKEMON_IN_PLAY_AREA
 	call GetTurnDuelistVariable
 	ld b, a
-	ld c, 0 ; PLAY_AREA_ARENA
+	ld c, PLAY_AREA_ARENA
 	ld e, c
 	ld d, c
 	ld hl, wPlayAreaAIScore
@@ -4601,7 +4661,7 @@ FindPlayAreaCardWithHighestAIScore: ; 167b5 (5:67b5)
 	ret
 
 ; same as above but only check bench Pokémon scores.
-.asm_167e1
+.only_bench
 	ld a, DUELVARS_NUMBER_OF_POKEMON_IN_PLAY_AREA
 	call GetTurnDuelistVariable
 	dec a
@@ -4624,6 +4684,7 @@ FindPlayAreaCardWithHighestAIScore: ; 167b5 (5:67b5)
 	dec b
 	jr nz, .loop_2
 
+; in this case, there is no minimum threshold AI score.
 	ld a, d
 	ldh [hTempPlayAreaLocation_ff9d], a
 	scf
@@ -4694,16 +4755,16 @@ GetEnergyCardForDiscardOrEnergyBoostAttack: ; 1683b (5:683b)
 	jr z, .first_attack
 
 ; check if second attack is Zapdos2's Thunderbolt,
-; Charizard's Fire Spin or Exeggcutor's Big Eggsplosion,
+; Charizard's Fire Spin or Exeggutor's Big Eggsplosion,
 ; for these to be treated differently.
 ; for both attacks, load its energy cost.
 	ld a, b
 	cp ZAPDOS2
 	jr z, .zapdos2
 	cp CHARIZARD
-	jr z, .charizard_or_exeggcutor
+	jr z, .charizard_or_exeggutor
 	cp EXEGGUTOR
-	jr z, .charizard_or_exeggcutor
+	jr z, .charizard_or_exeggutor
 	ld hl, wLoadedCard2Move2EnergyCost
 	jr .fire
 .first_attack
@@ -4758,9 +4819,9 @@ GetEnergyCardForDiscardOrEnergyBoostAttack: ; 1683b (5:683b)
 	or a
 	ret
 
-; Charizard's Fire Spin and Exeggcutor's Big Eggsplosion,
+; Charizard's Fire Spin and Exeggutor's Big Eggsplosion,
 ; return carry.
-.charizard_or_exeggcutor
+.charizard_or_exeggutor
 	lb bc, $00, $01
 	scf
 	ret
@@ -5019,11 +5080,13 @@ CheckSpecificDecksToAttachDoubleColorless: ; 1696e (5:696e)
 	ret
 ; 0x169ca
 
-Func_169ca: ; 169ca (5:69ca)
+; have AI choose an attack to use, but do not execute it.
+; return carry if an attack is chosen.
+AIProcessButDontUseAttack: ; 169ca (5:69ca)
 	ld a, $01
-	ld [wcdd9], a
+	ld [wAIExecuteProcessedAttack], a
 
-; copy wPlayAreaAIScore to wTempPlayAreaAIScore.
+; backup wPlayAreaAIScore in wTempPlayAreaAIScore.
 	ld de, wTempPlayAreaAIScore
 	ld hl, wPlayAreaAIScore
 	ld b, MAX_PLAY_AREA_POKEMON
@@ -5034,15 +5097,15 @@ Func_169ca: ; 169ca (5:69ca)
 	dec b
 	jr nz, .loop
 
-; copies wAIScore to wcde3
+; copies wAIScore to wTempAIScore
 	ld a, [wAIScore]
 	ld [de], a
-	jr Func_169fc
+	jr AIProcessAttacks
 
 ; copies wTempPlayAreaAIScore to wPlayAreaAIScore
-; and loads wAIscore with value in wcde3.
-; identical to Func_164d3.
-Func_169e3: ; 169e3 (5:69e3)
+; and loads wAIscore with value in wTempAIScore.
+; identical to RetrievePlayAreaAIScoreFromBackup1.
+RetrievePlayAreaAIScoreFromBackup2: ; 169e3 (5:69e3)
 	push af
 	ld de, wPlayAreaAIScore
 	ld hl, wTempPlayAreaAIScore
@@ -5060,12 +5123,18 @@ Func_169e3: ; 169e3 (5:69e3)
 	ret
 ; 0x169f8
 
-Func_169f8: ; 169f8 (5:69f8)
+; have AI choose and execute an attack.
+; return carry if an attack was chosen and attempted.
+AIProcessAndTryToUseAttack: ; 169f8 (5:69f8)
 	xor a
-	ld [wcdd9], a
+	ld [wAIExecuteProcessedAttack], a
 	; fallthrough
 
-Func_169fc: ; 169fc (5:69fc)
+; checks which of the Active card's attacks for AI to use.
+; If any of the attacks has enough AI score to be used,
+; AI will use it if wAIExecuteProcessedAttack is 0.
+; in either case, return carry if an attack is chosen to be used.
+AIProcessAttacks: ; 169fc (5:69fc)
 ; if AI used Pluspower, load its attack index
 	ld a, [wPreviousAIFlags]
 	and AI_FLAG_USED_PLUSPOWER
@@ -5077,23 +5146,23 @@ Func_169fc: ; 169fc (5:69fc)
 .no_pluspower
 	ld a, [wcda7]
 	cp $80
-	jp z, .asm_16a77
+	jp z, .dont_attack
 
 ; determine AI score of both attacks.
 	xor a ; FIRST_ATTACK_OR_PKMN_POWER
 	call GetAIScoreOfAttack
 	ld a, [wAIScore]
-	ld [wPlayAreaAIScore], a
+	ld [wFirstAttackAIScore], a
 	ld a, SECOND_ATTACK
 	call GetAIScoreOfAttack
 
 ; compare both attack scores
 	ld c, SECOND_ATTACK
-	ld a, [wPlayAreaAIScore]
+	ld a, [wFirstAttackAIScore]
 	ld b, a
 	ld a, [wAIScore]
 	cp b
-	jr nc, .asm_16a30
+	jr nc, .check_score
 	; first attack has higher score
 	dec c
 	ld a, b
@@ -5103,9 +5172,9 @@ Func_169fc: ; 169fc (5:69fc)
 ; first check if chosen attack has at least minimum score.
 ; then check if first attack is better than second attack
 ; in case the second one was chosen.
-.asm_16a30
+.check_score
 	cp $50 ; minimum score to use attack
-	jr c, .asm_16a77
+	jr c, .dont_attack
 	; enough score, proceed
 
 	ld a, c
@@ -5115,14 +5184,18 @@ Func_169fc: ; 169fc (5:69fc)
 	call CheckWhetherToSwitchToFirstAttack
 	
 .attack_chosen
-	ld a, [wcdd9]
+; check whether to execute the attack chosen
+	ld a, [wAIExecuteProcessedAttack]
 	or a
-	jr z, .asm_16a48
+	jr z, .execute
+
+; set carry and reset Play Area AI score
+; to the previous values.
 	scf
-	jp Func_169e3
+	jp RetrievePlayAreaAIScoreFromBackup2
 
-.asm_16a48
-	ld a, $0e
+.execute
+	ld a, AI_TRAINER_CARD_PHASE_14
 	call AIProcessHandTrainerCards
 
 ; load this attack's damage output against
@@ -5134,39 +5207,52 @@ Func_169fc: ; 169fc (5:69fc)
 	ld a, [wDamage]
 
 	or a
-	jr z, .asm_16a62
-	; if damage is 0, fallthrough
+	jr z, .check_damage_bench
+	; if damage is not 0, fallthrough
 
-.cannot_damage
+.can_damage
 	xor a
 	ld [wcdb4], a
-	jr .asm_16a6d
+	jr .use_attack
 
-.asm_16a62
+.check_damage_bench
+; check if it can otherwise damage player's bench
 	ld a, MOVE_FLAG1_ADDRESS | DAMAGE_TO_OPPONENT_BENCH_F
 	call CheckLoadedMoveFlag
-	jr c, .cannot_damage
+	jr c, .can_damage
+
+; cannot damage either Defending Pokemon or Bench
 	ld hl, wcdb4
 	inc [hl]
-.asm_16a6d
+
+; return carry if attack is chosen
+; and AI tries to use it.
+.use_attack
 	ld a, $01
 	ld [wcddb], a
-	call Func_14145
+	call AITryUseAttack
 	scf
 	ret
-.asm_16a77
-	ld a, [wcdd9]
+
+.dont_attack
+	ld a, [wAIExecuteProcessedAttack]
 	or a
-	jr z, .asm_16a80
-	jp Func_169e3
-.asm_16a80
+	jr z, .failed_to_use
+
+; reset Play Area AI score
+; to the previous values.
+	jp RetrievePlayAreaAIScoreFromBackup2
+
+; return no carry if no viable attack.
+.failed_to_use
 	ld hl, wcdb4
 	inc [hl]
 	or a
 	ret
 ; 0x16a86
 
-; determines the AI score of attack index in a.
+; determines the AI score of attack index in a
+; of card in Play Area location hTempPlayAreaLocation_ff9d.
 GetAIScoreOfAttack: ; 16a86 (5:6a86)
 ; initialize AI score.
 	ld [wSelectedAttack], a
@@ -5737,7 +5823,7 @@ HandleSpecialAIMoves: ; 16dcd (5:6dcd)
 	cp BELLSPROUT
 	jr z, HandleCallForFamily
 	cp EXEGGUTOR
-	jp z, HandleExeggcutorTeleport
+	jp z, HandleExeggutorTeleport
 	cp SCYTHER
 	jp z, HandleSwordsDanceAndFocusEnergy
 	cp KRABBY
@@ -5864,7 +5950,7 @@ HandleJigglypuff2FriendshipSong: ; 16ead (5:6ead)
 	ret
 
 ; if AI decides to retreat, return a score of $80 + 10.
-HandleExeggcutorTeleport: ; 16ec2 (5:6ec2)
+HandleExeggutorTeleport: ; 16ec2 (5:6ec2)
 	call AIDecideWhetherToRetreat
 	jp nc, HandleSpecialAIMoves.zero
 	ld a, $8a
@@ -5942,14 +6028,14 @@ HandlePorygonConversion: ; 16f18 (5:6f18)
 	jr nz, .conversion_2
 
 ; conversion 1
-	call CheckIfBenchCardsAreAtHalfHPCanEvolveAndUseSecondMove
+	call CountNumberOfSetUpBenchPokemon
 	cp 2
 	jr c, .low_score
 	ld a, $82
 	ret
 
 .conversion_2
-	call CheckIfBenchCardsAreAtHalfHPCanEvolveAndUseSecondMove
+	call CountNumberOfSetUpBenchPokemon
 	cp 2
 	jr nc, .low_score
 	ld a, $82
@@ -6097,7 +6183,7 @@ HandleElectrode1EnergySpike: ; 16ff2 (5:6ff2)
 	ld e, LIGHTNING_ENERGY
 	call CheckIfAnyCardIDinLocation
 	jp nc, HandleSpecialAIMoves.zero
-	call Func_164a1
+	call AIProcessButDontPlayEnergy_SkipEvolution
 	jp nc, HandleSpecialAIMoves.zero
 	ld a, $83
 	ret
@@ -6125,7 +6211,7 @@ HandleHyperBeam: ; 17005 (5:7005)
 CheckWhetherToSwitchToFirstAttack: ; 17019 (5:7019)
 ; this checks whether the first attack is also viable
 ; (has more than minimum score to be used)
-	ld a, [wPlayAreaAIScore]
+	ld a, [wFirstAttackAIScore]
 	cp $50
 	jr c, .keep_second_attack
 
@@ -6209,7 +6295,7 @@ CheckIfAnyBasicPokemonInDeck: ; 17057 (5:7057)
 ; return carry and that card's Play Area location in a.
 ; output:
 ;	a = card location of Pokémon card, if found;
-;	cerry set if such a card is found.
+;	carry set if such a card is found.
 LookForCardThatIsKnockedOutOnDevolution: ; 17080 (5:7080)
 	ldh a, [hTempPlayAreaLocation_ff9d]
 	push af
@@ -6307,15 +6393,16 @@ CheckIfArenaCardIsAtHalfHPCanEvolveAndUseSecondMove: ; 170c9 (5:70c9)
 	ret
 ; 0x17101
 
-; returns carry if at least one Pokémon in bench
-; meets the following conditions:
-;	- card HP >= half max HP
+; count Pokemon in the Bench that
+; meet the following conditions:
+;	- card HP > half max HP
 ;	- card Unknown2's 4 bit is not set or
 ;	  is set but there's no evolution of card in hand/deck
 ;	- card can use second move
-; Also outputs the number of Pokémon in bench
+; Outputs the number of Pokémon in bench
 ; that meet these requirements in a
-CheckIfBenchCardsAreAtHalfHPCanEvolveAndUseSecondMove: ; 17101 (5:7101)
+; and returns carry if at least one is found
+CountNumberOfSetUpBenchPokemon: ; 17101 (5:7101)
 	ldh a, [hTempPlayAreaLocation_ff9d]
 	ld d, a
 	ld a, [wSelectedAttack]
@@ -6333,17 +6420,24 @@ CheckIfBenchCardsAreAtHalfHPCanEvolveAndUseSecondMove: ; 17101 (5:7101)
 	push hl
 	cp $ff
 	jr z, .done
+
 	ld d, a
 	push de
 	push bc
 	call LoadCardDataToBuffer1_FromDeckIndex
 	pop bc
+
+; compares card's current HP with max HP
 	ld a, c
 	add DUELVARS_ARENA_CARD_HP
 	call GetTurnDuelistVariable
 	ld d, a
 	ld a, [wLoadedCard1HP]
 	rrca
+
+; a = max HP / 2
+; d = current HP
+; jumps if (current HP) <= (max HP / 2)
 	cp d
 	pop de
 	jr nc, .next
@@ -6386,8 +6480,138 @@ CheckIfBenchCardsAreAtHalfHPCanEvolveAndUseSecondMove: ; 17101 (5:7101)
 	ret
 ; 0x17161
 
-Func_17161 ; 17161 (5:7161)
-	INCROM $17161, $171fb
+; handles AI logic to determine some selections regarding certain attacks,
+; if any of these attacks were chosen to be used.
+; returns carry if selection was successful,
+; and no carry if unable to make one.
+; outputs in hTempPlayAreaLocation_ffa1 the chosen parameter.
+AISelectSpecialAttackParameters: ; 17161 (5:7161)
+	ld a, [wSelectedAttack]
+	push af
+	call .SelectAttackParameters
+	pop bc
+	ld a, b
+	ld [wSelectedAttack], a
+	ret
+; 0x1716e
+
+.SelectAttackParameters: ; 1716e (5:716e)
+	ld a, DUELVARS_ARENA_CARD
+	call GetTurnDuelistVariable
+	call GetCardIDFromDeckIndex
+	ld a, e
+	cp MEW3
+	jr z, .devolution_beam
+	cp MEWTWO3
+	jr z, .energy_absorption
+	cp MEWTWO2
+	jr z, .energy_absorption
+	cp EXEGGUTOR
+	jr z, .teleport
+	cp ELECTRODE1
+	jr z, .energy_spike
+	; fallthrough
+
+.no_carry
+	or a
+	ret
+
+.devolution_beam
+; in case selected attack is Devolution Beam
+; store in hTempPlayAreaLocation_ffa1
+; the location of card to select to devolve
+	ld a, [wSelectedAttack]
+	or a
+	jp z, .no_carry ; can be jr
+
+	ld a, $01
+	ldh [hTemp_ffa0], a
+	call LookForCardThatIsKnockedOutOnDevolution
+	ldh [hTempPlayAreaLocation_ffa1], a
+
+.set_carry_1
+	scf
+	ret
+
+.energy_absorption
+; in case selected attack is Energy Absorption
+; make list from energy cards in Discard Pile
+	ld a, [wSelectedAttack]
+	or a
+	jp nz, .no_carry  ; can be jr
+
+	ld a, $ff
+	ldh [hTempPlayAreaLocation_ffa1], a
+	ldh [hTempRetreatCostCards], a
+
+; search for Psychic energy cards in Discard Pile
+	ld e, PSYCHIC_ENERGY
+	ld a, CARD_LOCATION_DISCARD_PILE
+	call CheckIfAnyCardIDinLocation
+	ldh [hTemp_ffa0], a
+	farcall CreateEnergyCardListFromOpponentDiscardPile
+
+; find any energy card different from
+; the one found by CheckIfAnyCardIDinLocation.
+; since using this move requires a Psychic energy card,
+; and another one is in hTemp_ffa0,
+; then any other energy card would account
+; for the Energy Cost of Psyburn.
+	ld hl, wDuelTempList
+.loop_energy_cards
+	ld a, [hli]
+	cp $ff
+	jr z, .set_carry_2
+	ld b, a
+	ldh a, [hTemp_ffa0]
+	cp b
+	jr z, .loop_energy_cards ; same card, keep looking
+
+; store the deck index of energy card found
+	ld a, b
+	ldh [hTempPlayAreaLocation_ffa1], a
+	; fallthrough
+
+.set_carry_2
+	scf
+	ret
+
+.teleport
+; in case selected attack is Teleport
+; decide Bench card to switch to.
+	ld a, [wSelectedAttack]
+	or a
+	jp nz, .no_carry  ; can be jr
+	call AIDecideBenchPokemonToSwitchTo
+	jr c, .no_carry
+	ldh [hTemp_ffa0], a
+	scf
+	ret
+
+.energy_spike
+; in case selected attack is Energy Spike
+; decide basic energy card to fetch from Deck.
+	ld a, [wSelectedAttack]
+	or a
+	jp z, .no_carry  ; can be jr
+
+	ld a, CARD_LOCATION_DECK
+	ld e, LIGHTNING_ENERGY
+
+; if none were found in Deck, return carry...
+	call CheckIfAnyCardIDinLocation
+	ldh [hTemp_ffa0], a
+	jp nc, .no_carry  ; can be jr
+
+; ...else find a suitable Play Area Pokemon to
+; attach the energy card to.
+	call AIProcessButDontPlayEnergy_SkipEvolution
+	jp nc, .no_carry  ; can be jr
+	ldh a, [hTempPlayAreaLocation_ff9d]
+	ldh [hTempPlayAreaLocation_ffa1], a
+	scf
+	ret
+; 0x171fb
 
 ; return carry if Pokémon at play area location
 ; in hTempPlayAreaLocation_ff9d does not have
@@ -6591,7 +6815,7 @@ CheckIfCanDamageDefendingPokemon: ; 17383 (5:7383)
 ; sets carry if any on the moves knocks out
 ; also outputs the largest damage dealt in a
 ; input:
-;	[hTempPlayAreaLocation_ff9d] = locaion of card to check
+;	[hTempPlayAreaLocation_ff9d] = location of card to check
 ; output:
 ;	a = largest damage of both moves
 ;	carry set if can knock out
@@ -6825,7 +7049,7 @@ CheckForBenchIDAtHalfHPAndCanUseSecondMove: ; 17474 (5:7474)
 	ret
 ; 0x174cd
 
-; add 5 to wcde4 AI score corresponding to all cards
+; add 5 to wPlayAreaEnergyAIScore AI score corresponding to all cards
 ; in bench that have same ID as register a
 ; input:
 ;	a = card ID to look for
@@ -6848,7 +7072,7 @@ RaiseAIScoreToAllMatchingIDsInBench: ; 174cd (5:74cd)
 	ld c, e
 	ld b, $00
 	push hl
-	ld hl, wcde4
+	ld hl, wPlayAreaEnergyAIScore
 	add hl, bc
 	ld a, 5
 	add [hl]
@@ -6860,8 +7084,8 @@ RaiseAIScoreToAllMatchingIDsInBench: ; 174cd (5:74cd)
 ; goes through each play area Pokémon, and
 ; for all cards of the same ID, determine which
 ; card has highest value calculated from Func_17583
-; the card with highest value gets increased wcde4
-; while all others get decreased wcde4
+; the card with highest value gets increased wPlayAreaEnergyAIScore
+; while all others get decreased wPlayAreaEnergyAIScore
 Func_174f2: ; 174f2 (5:74f2)
 	ld a, MAX_PLAY_AREA_POKEMON
 	ld hl, wcdfa
@@ -6880,6 +7104,7 @@ Func_174f2: ; 174f2 (5:74f2)
 	ld a, [hli]
 	cp $ff
 	ret z
+
 	ld [wcdf9], a
 	push de
 	push hl
@@ -6945,11 +7170,11 @@ Func_174f2: ; 174f2 (5:74f2)
 	jr .loop_2
 
 ; c = play area location of highest score
-; decrease wcde4 score for all cards with same ID
+; decrease wPlayAreaEnergyAIScore score for all cards with same ID
 ; except for the one with highest score
-; increase wcde4 score for card with highest ID
+; increase wPlayAreaEnergyAIScore score for card with highest ID
 .asm_17560
-	ld hl, wcde4
+	ld hl, wPlayAreaEnergyAIScore
 	ld de, wcdea
 	ld b, PLAY_AREA_ARENA
 .loop_3
diff --git a/src/engine/bank08.asm b/src/engine/bank08.asm
index 5a0f535..6850b82 100644
--- a/src/engine/bank08.asm
+++ b/src/engine/bank08.asm
@@ -6219,8 +6219,449 @@ AIDecide_PokemonTrader_Flamethrower: ; 22133 (8:6133)
 	ret
 ; 0x2219b
 
-Func_2219b: ; 2219b (8:219b)
-	INCROM $2219b, $227f6
+; handle AI routines for Energy Trans.
+; depending on input, AI can use Energy Trans to
+; give Arena or Bench cards some Grass energy cards,
+; depending whether it's for attack, retreat, etc.
+HandleAIEnergyTrans: ; 2219b (8:619b)
+	ld [wce06], a
+
+; choose to randomly return
+	farcall ChooseRandomlyNotToPlayTrainerCard
+	ret c
+
+	ld a, DUELVARS_NUMBER_OF_POKEMON_IN_PLAY_AREA
+	call GetTurnDuelistVariable
+	dec a
+	ret z ; return if no Bench cards
+
+	ld a, VENUSAUR2
+	call CountPokemonIDInPlayArea
+	ret nc ; return if no Venusaur2 found in own Play Area
+
+	ld a, MUK
+	call CountPokemonIDInBothPlayAreas
+	ret c ; return if Muk found in any Play Area
+
+	ld a, [wce06]
+	cp $09
+	jr z, .check_retreat
+
+	cp $0e
+	jp z, .TransferEnergyToBench
+
+	call .CheckEnoughGrassEnergyCardsForAttack
+	ret nc
+	jr .TransferEnergyToArena
+
+.check_retreat
+	call .CheckEnoughGrassEnergyCardsForRetreatCost
+	ret nc
+
+; use Energy Trans to transfer number of Grass energy cards
+; equal to input a from the Bench to the Arena card.
+.TransferEnergyToArena
+	ld [wAINumberOfEnergyTransCards], a
+
+; look for Venusaur2 in Play Area
+; so that its PKMN Power can be used.
+	ld a, DUELVARS_NUMBER_OF_POKEMON_IN_PLAY_AREA
+	call GetTurnDuelistVariable
+	dec a
+	ld b, a
+.loop_play_area_1
+	ld a, DUELVARS_ARENA_CARD
+	add b
+	call GetTurnDuelistVariable
+	ldh [hTempCardIndex_ff9f], a
+	call GetCardIDFromDeckIndex
+	ld a, e
+	cp VENUSAUR2
+	jr z, .use_pkmn_power_1
+
+	ld a, b
+	or a
+	ret z ; return when finished Play Area loop
+
+	dec b
+	jr .loop_play_area_1
+
+; use Energy Trans Pkmn Power
+.use_pkmn_power_1
+	ld a, b
+	ldh [hTemp_ffa0], a
+	ld a, OPPACTION_USE_PKMN_POWER
+	bank1call AIMakeDecision
+	ld a, OPPACTION_EXECUTE_PKMN_POWER_EFFECT
+	bank1call AIMakeDecision
+
+	xor a ; PLAY_AREA_ARENA
+	ldh [hAIEnergyTransPlayAreaLocation], a
+	ld a, [wAINumberOfEnergyTransCards]
+	ld d, a
+
+; look for Grass energy cards that
+; are currently attached to a Bench card.
+	ld e, 0
+.loop_deck_locations_1
+	ld a, DUELVARS_CARD_LOCATIONS
+	add e
+	call GetTurnDuelistVariable
+	and %00011111
+	cp CARD_LOCATION_BENCH_1
+	jr c, .next_card_1
+
+	and %00001111
+	ldh [hTempPlayAreaLocation_ffa1], a
+
+	ld a, e
+	push de
+	call GetCardIDFromDeckIndex
+	ld a, e
+	pop de
+	cp GRASS_ENERGY
+	jr nz, .next_card_1
+
+	; store the deck index of energy card
+	ld a, e
+	ldh [hAIEnergyTransEnergyCard], a
+
+	push de
+	ld d, 30
+.small_delay_1
+	call DoFrame
+	dec d
+	jr nz, .small_delay_1
+
+	ld a, OPPACTION_6B15
+	bank1call AIMakeDecision
+	pop de
+	dec d
+	jr z, .done_transfer_1
+
+.next_card_1
+	inc e
+	ld a, DECK_SIZE
+	cp e
+	jr nz, .loop_deck_locations_1
+
+; transfer is done, perform delay
+; and return to main scene.
+.done_transfer_1
+	ld d, 60
+.big_delay_1
+	call DoFrame
+	dec d
+	jr nz, .big_delay_1
+	ld a, OPPACTION_DUEL_MAIN_SCENE
+	bank1call AIMakeDecision
+	ret
+; 0x22246
+
+; checks if the Arena card has not enough energy for second attack,
+; and if not, return carry if transferring Grass energy from Bench
+; would be enough to use it and outputs number of energy cards needed in a.
+.CheckEnoughGrassEnergyCardsForAttack ; 22246 (8:6246)
+	ld a, DUELVARS_ARENA_CARD
+	call GetTurnDuelistVariable
+	call GetCardIDFromDeckIndex
+	ld a, e
+	cp EXEGGUTOR
+	jr z, .is_exeggutor
+
+	xor a ; PLAY_AREA_ARENA
+	ldh [hTempPlayAreaLocation_ff9d], a
+	ld a, SECOND_ATTACK
+	ld [wSelectedAttack], a
+	farcall CheckEnergyNeededForAttack
+	jr nc, .attack_false ; return if no energy needed
+
+; check if colorless energy is needed...
+	ld a, c
+	or a
+	jr nz, .count_if_enough
+
+; ...otherwise check if basic energy card is needed
+; and it's grass energy.
+	ld a, b
+	or a
+	jr z, .attack_false
+	ld a, e
+	cp GRASS_ENERGY
+	jr nz, .attack_false
+	ld c, b
+	jr .count_if_enough
+
+.attack_false
+	or a
+	ret
+
+.count_if_enough
+; if there's enough Grass energy cards in Bench
+; to satisfy the attack energy cost, return carry.
+	push bc
+	call .CountGrassEnergyInBench
+	pop bc
+	cp c
+	jr c, .attack_false
+	ld a, c
+	scf
+	ret
+
+.is_exeggutor
+; in case it's Exeggutor in Arena, return carry
+; if there are any Grass energy cards in Bench.
+	call .CountGrassEnergyInBench
+	or a
+	jr z, .attack_false
+
+	scf
+	ret
+; 0x22286
+
+; outputs in a the number of Grass energy cards
+; currently attached to Bench cards.
+.CountGrassEnergyInBench ; 22286 (8:6286)
+	lb de, 0, 0
+.count_loop
+	ld a, DUELVARS_CARD_LOCATIONS
+	add e
+	call GetTurnDuelistVariable
+	and %00011111
+	cp CARD_LOCATION_BENCH_1
+	jr c, .count_next
+
+; is in bench
+	ld a, e
+	push de
+	call GetCardIDFromDeckIndex
+	ld a, e
+	pop de
+	cp GRASS_ENERGY
+	jr nz, .count_next
+	inc d
+.count_next
+	inc e
+	ld a, DECK_SIZE
+	cp e
+	jr nz, .count_loop
+	ld a, d
+	ret
+; 0x222a9
+
+; returns carry if there are enough Grass energy cards in Bench
+; to satisfy the retreat cost of the Arena card.
+; if so, output the number of energy cards still needed in a.
+.CheckEnoughGrassEnergyCardsForRetreatCost ; 222a9 (8:62a9)
+	xor a ; PLAY_AREA_ARENA
+	ldh [hTempPlayAreaLocation_ff9d], a
+	call GetPlayAreaCardRetreatCost
+	ld b, a
+	ld e, PLAY_AREA_ARENA
+	farcall CountNumberOfEnergyCardsAttached
+	cp b
+	jr nc, .retreat_false ; return if enough to retreat
+
+; see if there's enough Grass energy cards
+; in the Bench to satisfy retreat cost
+	ld c, a
+	ld a, b
+	sub c
+	ld c, a
+	push bc
+	call .CountGrassEnergyInBench
+	pop bc
+	cp c
+	jr c, .retreat_false ; return if less cards than needed
+
+; output number of cards needed to retreat
+	ld a, c
+	scf
+	ret
+.retreat_false
+	or a
+	ret
+; 0x222ca
+
+; AI logic to determine whether to use Energy Trans Pkmn Power
+; to transfer energy cards attached from the Arena Pokemon to
+; some card in the Bench.
+.TransferEnergyToBench ; 222ca (8:62ca)
+	xor a ; PLAY_AREA_ARENA
+	ldh [hTempPlayAreaLocation_ff9d], a
+	farcall CheckIfDefendingPokemonCanKnockOut
+	ret nc ; return if Defending can't KO
+
+; processes attacks and see if any attack would be used by AI.
+; if so, return.
+	farcall AIProcessButDontUseAttack
+	ret c
+
+; return if Arena card has no Grass energy cards attached.
+	ld e, PLAY_AREA_ARENA
+	call GetPlayAreaCardAttachedEnergies
+	ld a, [wAttachedEnergies + GRASS]
+	or a
+	ret z
+
+; if no energy card attachment is needed, return.
+	farcall AIProcessButDontPlayEnergy_SkipEvolutionAndArena
+	ret nc
+
+; AI decided that an energy card is needed
+; so look for Venusaur2 in Play Area
+; so that its PKMN Power can be used.
+	ld a, DUELVARS_NUMBER_OF_POKEMON_IN_PLAY_AREA
+	call GetTurnDuelistVariable
+	dec a
+	ld b, a
+.loop_play_area_2
+	ld a, DUELVARS_ARENA_CARD
+	add b
+	call GetTurnDuelistVariable
+	ldh [hTempCardIndex_ff9f], a
+	ld [wAIVenusaur2DeckIndex], a
+	call GetCardIDFromDeckIndex
+	ld a, e
+	cp VENUSAUR2
+	jr z, .use_pkmn_power_2
+
+	ld a, b
+	or a
+	ret z ; return when Play Area loop is ended
+
+	dec b
+	jr .loop_play_area_2
+
+; use Energy Trans Pkmn Power
+.use_pkmn_power_2
+	ld a, b
+	ldh [hTemp_ffa0], a
+	ld [wAIVenusaur2PlayAreaLocation], a
+	ld a, OPPACTION_USE_PKMN_POWER
+	bank1call AIMakeDecision
+	ld a, OPPACTION_EXECUTE_PKMN_POWER_EFFECT
+	bank1call AIMakeDecision
+
+; loop for each energy cards that are going to be transferred.
+.loop_energy
+	xor a
+	ldh [hTempPlayAreaLocation_ffa1], a
+	ld a, [wAIVenusaur2PlayAreaLocation]
+	ldh [hTemp_ffa0], a
+
+	; returns when Arena card has no Grass energy cards attached.
+	ld e, PLAY_AREA_ARENA
+	call GetPlayAreaCardAttachedEnergies
+	ld a, [wAttachedEnergies + GRASS]
+	or a
+	jr z, .done_transfer_2
+
+; look for Grass energy cards that
+; are currently attached to Arena card.
+	ld e, 0
+.loop_deck_locations_2
+	ld a, DUELVARS_CARD_LOCATIONS
+	add e
+	call GetTurnDuelistVariable
+	cp CARD_LOCATION_ARENA
+	jr nz, .next_card_2
+
+	ld a, e
+	push de
+	call GetCardIDFromDeckIndex
+	ld a, e
+	pop de
+	cp GRASS_ENERGY
+	jr nz, .next_card_2
+
+	; store the deck index of energy card
+	ld a, e
+	ldh [hAIEnergyTransEnergyCard], a
+	jr .transfer
+
+.next_card_2
+	inc e
+	ld a, DECK_SIZE
+	cp e
+	jr nz, .loop_deck_locations_2
+	jr .done_transfer_2
+
+.transfer
+; get the Bench card location to transfer Grass energy card to.
+	farcall AIProcessButDontPlayEnergy_SkipEvolutionAndArena
+	jr nc, .done_transfer_2
+	ldh a, [hTempPlayAreaLocation_ff9d]
+	ldh [hAIEnergyTransPlayAreaLocation], a
+
+	ld d, 30
+.small_delay_2
+	call DoFrame
+	dec d
+	jr nz, .small_delay_2
+
+	ld a, [wAIVenusaur2DeckIndex]
+	ldh [hTempCardIndex_ff9f], a
+	ld d, a
+	ld e, FIRST_ATTACK_OR_PKMN_POWER
+	call CopyMoveDataAndDamage_FromDeckIndex
+	ld a, OPPACTION_6B15
+	bank1call AIMakeDecision
+	jr .loop_energy
+
+; transfer is done, perform delay
+; and return to main scene.
+.done_transfer_2
+	ld d, 60
+.big_delay_2
+	call DoFrame
+	dec d
+	jr nz, .big_delay_2
+	ld a, OPPACTION_DUEL_MAIN_SCENE
+	bank1call AIMakeDecision
+	ret
+; 0x2237f
+
+Func_2237f: ; 2237f (8:237f)
+	INCROM $2237f, $2262d
+
+Func_2262d: ; 2262d (8:262d)
+	INCROM $2262d, $226a3
+
+Func_226a3: ; 226a3 (8:26a3)
+	INCROM $226a3, $22790
+
+Func_22790: ; 22790 (8:2790)
+	INCROM $22790, $227d3
+
+; checks wcda7 and Pokemon in Play Area that are set up.
+; if there's at least 4, goes to AI_TRAINER_CARD_PHASE_05.
+; else, returns carry.
+Func_227d3: ; 227d3 (8:67d3)
+	ld a, [wcda7]
+	bit 7, a
+	jr z, .set_carry
+	cp %10000010
+	jr c, .asm_227e4
+
+	xor a
+	ld [wcda7], a
+	jr .set_carry
+
+.asm_227e4
+	farcall CountNumberOfSetUpBenchPokemon
+	cp 4
+	jr c, .set_carry
+
+	ld a, AI_TRAINER_CARD_PHASE_05
+	farcall AIProcessHandTrainerCards
+	or a
+	ret
+
+.set_carry
+	scf
+	ret
+; 0x227f6
 
 ; lists in wDuelTempList all the basic energy cards
 ; in card location of a.
@@ -7128,7 +7569,7 @@ FindDuplicatePokemonCards: ; 22b6f (8:6b6f)
 
 ; return carry flag if move is not high recoil.
 Func_22bad: ; 22bad (8:6bad)
-	farcall Func_169ca
+	farcall AIProcessButDontUseAttack
 	ret nc
 	ld a, [wSelectedAttack]
 	ld e, a
diff --git a/src/engine/effect_functions.asm b/src/engine/effect_functions.asm
index 8832134..dbda9ad 100644
--- a/src/engine/effect_functions.asm
+++ b/src/engine/effect_functions.asm
@@ -292,7 +292,9 @@ ApplySubstatus2ToDefendingCard: ; 2c149 (b:4149)
 	ret
 ; 0x2c166
 
-Func_2c166: ; 2c166 (b:4166)
+; overwrites in wDamage, wAIMinDamage and wAIMaxDamage
+; with the value in a.
+StoreDamageInfo: ; 2c166 (b:4166)
 	ld [wDamage], a
 	ld [wAIMinDamage], a
 	ld [wAIMaxDamage], a
@@ -348,7 +350,77 @@ HandleSwitchDefendingPokemonEffect: ; 2c1ec (b:41ec)
 	ret
 ; 0x2c221
 
-	INCROM $2c221, $2c487
+	INCROM $2c221, $2c2a4
+
+; makes a list in wDuelTempList with the deck indices
+; of all the energy cards found in opponent's Discard Pile.
+; if (c == 0), all energy cards are allowed;
+; if (c != 0), double colorless energy cards are not counted.
+; returns carry if no energy cards were found.
+CreateEnergyCardListFromOpponentDiscardPile: ; 2c2a4 (b:42a4)
+	ld c, $00
+
+; get number of cards in Discard Pile
+; and have hl point to the end of the
+; Discard Pile list in wOpponentDeckCards.
+	ld a, DUELVARS_NUMBER_OF_CARDS_IN_DISCARD_PILE
+	call GetTurnDuelistVariable
+	ld b, a
+	add DUELVARS_DECK_CARDS
+	ld l, a
+
+	ld de, wDuelTempList
+	inc b
+	jr .next_card
+
+.check_energy
+	ld a, [hl]
+	call LoadCardDataToBuffer2_FromDeckIndex
+	ld a, [wLoadedCard2Type]
+	and TYPE_ENERGY
+	jr z, .next_card
+
+; if (c != $00), then we dismiss Double Colorless
+; energy cards found.
+	ld a, c
+	or a
+	jr z, .copy
+	ld a, [wLoadedCard2Type]
+	cp TYPE_ENERGY_DOUBLE_COLORLESS
+	jr nc, .next_card
+
+.copy
+	ld a, [hl]
+	ld [de], a
+	inc de
+
+; goes through Discard Pile list
+; in wOpponentDeckCards in descending order.
+.next_card
+	dec l
+	dec b
+	jr nz, .check_energy
+
+; terminating byte on wDuelTempList
+	ld a, $ff
+	ld [de], a
+
+; check if any energy card was found
+; by checking whether the first byte
+; in wDuelTempList is $ff.
+; if none were found, return carry.
+	ld a, [wDuelTempList]
+	cp $ff
+	jr z, .set_carry
+	or a
+	ret
+
+.set_carry
+	scf
+	ret
+; 0x2c2e0
+
+	INCROM $2c2e0, $2c487
 
 ; handles the selection of a forced switch
 ; by link/AI opponent or by the player.
@@ -558,7 +630,7 @@ Twineedle_MultiplierEffect: ; 2c7f5 (b:47f5)
 	add a
 	add e
 	call ATimes10
-	call Func_2c166
+	call StoreDamageInfo
 	ret
 ; 0x2c80d
 
@@ -679,4 +751,16 @@ Toxic_DoublePoisonEffect: ; 2c994 (b:4994)
 	ret
 ; 0x2c998
 
-	INCROM $2c998, $30000
\ No newline at end of file
+	INCROM $2c998, $2cbfb
+
+Func_2cbfb: ; 2cbfb (b:4bfb)
+	ldh a, [hAIEnergyTransPlayAreaLocation]
+	ld e, a
+	ldh a, [hAIEnergyTransEnergyCard]
+	call AddCardToHand
+	call PutHandCardInPlayArea
+	bank1call PrintPlayAreaCardList_EnableLCD
+	ret
+; 0x2cc0a
+
+	INCROM $2cc0a, $30000
\ No newline at end of file
diff --git a/src/engine/home.asm b/src/engine/home.asm
index 4f9fc31..338dbb0 100644
--- a/src/engine/home.asm
+++ b/src/engine/home.asm
@@ -5218,7 +5218,7 @@ Func_1bca: ; 1bca (0:1bca)
 	ret
 ; 0x1c05
 
-; return in a the retreat cost of the turn holder's arena or benchx Pokemon
+; return in a the retreat cost of the turn holder's arena or bench Pokemon
 ; given the PLAY_AREA_* value in hTempPlayAreaLocation_ff9d
 GetPlayAreaCardRetreatCost: ; 1c05 (0:1c05)
 	ldh a, [hTempPlayAreaLocation_ff9d]
diff --git a/src/hram.asm b/src/hram.asm
index 9cdba06..2b4fbc9 100644
--- a/src/hram.asm
+++ b/src/hram.asm
@@ -85,10 +85,24 @@ hTemp_ffa0:: ; ffa0
 hTempPlayAreaLocation_ffa1:: ; ffa1
 	ds $1
 
+UNION
+
 ; $ff-terminated list of cards to be discarded upon retreat
 hTempRetreatCostCards:: ; ffa2
 	ds $6
 
+NEXTU
+
+; parameters chosen by AI in Energy Trans routine.
+; the deck index (0-59) of the energy card to transfer
+; and the Play Area location (PLAY_AREA_*) of card to receive that energy card.
+hAIEnergyTransEnergyCard:: ; ffa2
+	ds $1
+hAIEnergyTransPlayAreaLocation:: ; ffa3
+	ds $1
+
+ENDU
+
 ; hffa8 through hffb0 belong to the text engine
 hffa8:: ; ffa8
 	ds $1
diff --git a/src/wram.asm b/src/wram.asm
index e5fc9c6..2a10fe2 100644
--- a/src/wram.asm
+++ b/src/wram.asm
@@ -1230,11 +1230,21 @@ wTempCardType:: ; cdba
 wAIScore:: ; cdbe
 	ds $1
 
+UNION
+
 ; used for AI decisions that involve
 ; each card in the Play Area.
 wPlayAreaAIScore:: ; cdbf
 	ds MAX_PLAY_AREA_POKEMON
 
+NEXTU
+
+; stores the score determined by AI for first attack
+wFirstAttackAIScore:: ; cdbf
+	ds $1
+
+ENDU
+
 	ds $0a
 
 ; information about the defending Pokémon and
@@ -1274,10 +1284,16 @@ wAIPluspowerAttack:: ; cdd6
 wAIPlayEnergyCardForRetreat:: ; cdd7
 	ds $1
 
-wcdd8:: ; cdd8
+; flags defined by AI_ENERGY_FLAG_* constants
+; used as input for AIProcessEnergyCards
+; to determine what to check in the routine.
+wAIEnergyAttachLogicFlags:: ; cdd8
 	ds $1
 
-wcdd9:: ; cdd9
+; used as input to AIProcessAttacks.
+; if 0, execute the attack chosen by the AI.
+; if not 0, return without executing attack.
+wAIExecuteProcessedAttack:: ; cdd9
 	ds $1
 
 wcdda:: ; cdda
@@ -1289,15 +1305,17 @@ wcddb:: ; cddb
 wcddc:: ; cddc
 	ds $1
 
-; used to compliment wPlayAreaAIScore,
-; to temporarily do calculations and store results.
+; used to temporarily backup wPlayAreaAIScore values.
 wTempPlayAreaAIScore:: ; cddd
 	ds MAX_PLAY_AREA_POKEMON
 
-wcde3:: ; cde3
+wTempAIScore:: ; cde3
 	ds $1
 
-wcde4:: ; cde4
+; used for AI decisions that involve
+; each card in the Play Area involving
+; attaching Energy cards.
+wPlayAreaEnergyAIScore:: ; cde4
 	ds MAX_PLAY_AREA_POKEMON
 
 wcdea:: ; cdea
@@ -1355,8 +1373,15 @@ wAIMoveIsNonDamaging:: ; ce02
 wce03:: ; ce03
 	ds $1
 
-	ds $2
+; used by AI to store information of Venusaur2
+; while handling Energy Trans logic.
+wAIVenusaur2DeckIndex:: ; ce04
+	ds $1
+wAIVenusaur2PlayAreaLocation:: ; ce05
+	ds $1
 
+; number of cards to be transferred by AI using Energy Trans.
+wAINumberOfEnergyTransCards::
 wce06:: ; ce06
 	ds $1