diff --git a/data/items/key_items.asm b/data/items/key_items.asm
index 528374c1..773db5b4 100644
--- a/data/items/key_items.asm
+++ b/data/items/key_items.asm
@@ -75,7 +75,7 @@ KeyItemFlags:
 	dbit TRUE  ; POKE_FLUTE
 	dbit TRUE  ; LIFT_KEY
 	dbit FALSE ; EXP_ALL
-	dbit FALSE  ; was TRUE for OLD_ROD, now CANDY_SACK
+	dbit TRUE  ; was TRUE for OLD_ROD, now CANDY_JAR
 	dbit FALSE  ; was GOOD_ROD & TRUE, now BOTTLE_CAP
 	dbit TRUE  ; SUPER_ROD
 	dbit FALSE ; PP_UP
diff --git a/data/text/text_2.asm b/data/text/text_2.asm
index 4dc2139c..4fbeae07 100644
--- a/data/text/text_2.asm
+++ b/data/text/text_2.asm
@@ -1834,3 +1834,10 @@ _MysteryBoxCloseText::
 	text "<PLAYER> closed"
 	line "the BOX!"
 	prompt
+
+_CandyJarCount::
+	text "MELTAN CANDY:"
+	line "@"
+	text_bcd wCandyJarCount, 2 | LEADING_ZEROES | LEFT_ALIGN
+	text "0"
+	prompt
\ No newline at end of file
diff --git a/engine/battle/core.asm b/engine/battle/core.asm
index ad534594..b0bfdff0 100644
--- a/engine/battle/core.asm
+++ b/engine/battle/core.asm
@@ -839,6 +839,26 @@ FaintEnemyPokemon:
 	call PrintText
 	call PrintEmptyString
 	call SaveScreenTilesToBuffer1
+	
+	; Meltan Candy functionality.
+	; The way this is done looks like it conflates 8- and 16-bit integers, but it never goes above 256, so it'll be fine.
+	ld a, [wEnemyMonSpecies] ; Load species.
+	cp $E7 ; Is it Meltan?
+	jr nz, .skip ; Continue as normal if not.
+	
+	; For engine\overworld\clear_variables.asm
+	; Needed so the Mystery Box effect isn't cleared upon leaving battle.
+	ld a, $01
+	ld [wDontSwitchOffMysteryBoxYet], a
+	
+	ld a, [wCandyJarCount]
+	inc a
+	ld [wCandyJarCount], a
+	
+	ld hl, MeltanIncrement ; Load text to show it's going up.
+	call PrintText ; Yep text.
+	call PrintEmptyString ; vs text likes this.
+.skip
 	xor a
 	ld [wBattleResult], a
 	ld a, [wCurMap]
@@ -7173,3 +7193,8 @@ StupidBattleTentFix:
 	text "Oops! Better"
 	line "luck next time!"
 	prompt
+
+MeltanIncrement:
+	text "<PLAYER> found"
+	line "10 MELTAN CANDY!"
+	prompt
diff --git a/engine/debug/debug_party.asm b/engine/debug/debug_party.asm
index fd0c6ad1..15641325 100644
--- a/engine/debug/debug_party.asm
+++ b/engine/debug/debug_party.asm
@@ -22,12 +22,11 @@ SetIshiharaTeam:
 
 IshiharaTeam:
 	db EXEGGUTOR_A, 90
-	db PURAKKUSU, 90
+	db MELTAN, 90
 	db TRAMPEL, 90
 IF DEF(_DEBUG)
 	db TAUROS_PB, 90
 	db SNORLAX, 50
-	db TANGROWTH, 50
 ENDC
 	db -1 ; end
 
@@ -162,6 +161,7 @@ DebugSetPokedexEntries:
 
 DebugItemsList:
 	db MYSTERY_BOX, 1
+	db CANDY_JAR, 1
 	db BICYCLE, 1
 	db FULL_RESTORE, 99
 	db MAX_REPEL, 99
diff --git a/engine/items/item_effects.asm b/engine/items/item_effects.asm
index d44cce12..59e333f6 100644
--- a/engine/items/item_effects.asm
+++ b/engine/items/item_effects.asm
@@ -92,7 +92,7 @@ ItemUsePtrTable:
 	dw ItemUsePokeflute  ; POKE_FLUTE
 	dw UnusableItem      ; LIFT_KEY
 	dw UnusableItem      ; EXP_ALL
-	dw ItemUseEvoStone    ; was OLD_ROD, now CANDY_SACK
+	dw ItemUseCandyJar    ; was OLD_ROD, now CANDY_JAR
 	dw UnusableItem    ; was GOOD_ROD, now BOTTLE_CAP
 	dw ItemUseSuperRod   ; SUPER_ROD
 	dw ItemUsePPUp       ; PP_UP (real one)
@@ -138,6 +138,21 @@ ItemUseMysteryBox:
 	call PrintText
 	jp TextScriptEnd
 
+ItemUseCandyJar:
+	; Candy Jar can't be used in battle.
+	ld a, [wIsInBattle]
+	and a
+	jp nz, ItemUseNotTime
+	
+	ld [wCandyJarCount], a ; Get the Candy count
+	cp 40 ; Is it 40? (represented as 400)
+	jr z, .Evolve ; If yes, jump to Evo Stone Script
+	ld hl, CandyJarCount ; Otherwise, load the Candy total...
+	call PrintText ; and display it as text.
+	jp TextScriptEnd ; se acabo!
+.Evolve ; Evo stone script time
+	jp ItemUseEvoStone ; Jump there!
+
 ItemUseBall:
 
 ; Balls can't be used out of battle.
@@ -824,10 +839,20 @@ ItemUseEvoStone:
 	jr z, .noEffect
 	pop af
 	ld [wWhichPokemon], a
+	
+	; The Candy Jar jumps here to save space if it's capable of evolving Meltan.
+	; However, we don't want it to leave the inventory - we want it to lose the candy.
+	ld a, [wEvoStoneItemID] ; Load the item ID we just got
+	cp CANDY_JAR ; Is it the Candy Jar?
+	jr z, .zeroOutJar ; If return zero (true), save the Jar from destruction.
 	ld hl, wNumBagItems
 	ld a, 1 ; remove 1 stone
 	ld [wItemQuantity], a
 	jp RemoveItemFromInventory
+.zeroOutJar
+	ld a, $0
+	ld [wCandyJarCount], a
+	ret
 .noEffect
 	call ItemUseNoEffect
 .canceledItemUse
@@ -2998,3 +3023,7 @@ CheckMapForMon:
 MysteryBoxText:
 	text_far _MysteryBoxText
 	text_end
+
+CandyJarCount:
+	text_far _CandyJarCount
+	text_end
diff --git a/engine/overworld/clear_variables.asm b/engine/overworld/clear_variables.asm
index 185c64bd..8fff93a6 100644
--- a/engine/overworld/clear_variables.asm
+++ b/engine/overworld/clear_variables.asm
@@ -10,11 +10,20 @@ ClearVariablesOnEnterMap::
 	ldh [hJoyReleased], a
 	ldh [hJoyHeld], a
 	ld [wActionResultOrTookBattleTurn], a
-	ld [wMysteryBoxActive], a
 	ld hl, wCardKeyDoorY
 	ld [hli], a
 	ld [hl], a
 	ld hl, wWhichTrade
 	ld bc, wStandingOnWarpPadOrHole - wWhichTrade
 	call FillMemory
+	
+	; The Mystery Box for Meltan gets switched off when leaving every map, but SPECIFICALLY not after a battle.
+	; Because leaving battle is map re-entry, this exception is included.
+	ld a, [wDontSwitchOffMysteryBoxYet] ; Load WRAM bit.
+	and a ; Did a battle just happen?
+	jr nz, .skip ; Yes? Off you go then.
+	ld a, $0 ; No? Let's zero both of these out then.
+	ld [wMysteryBoxActive], a ; This is now deactivated.
+	ld [wDontSwitchOffMysteryBoxYet], a ; To be activated when a Meltan is defeated later.
+.skip
 	ret
diff --git a/ram/wram.asm b/ram/wram.asm
index f76ba126..550e1af2 100644
--- a/ram/wram.asm
+++ b/ram/wram.asm
@@ -2131,7 +2131,6 @@ wObtainedHiddenCoinsFlags:: flag_array 16
 ; $01 = biking
 ; $02 = surfing
 wWalkBikeSurfState:: db
-
 	ds 10
 
 wTownVisitedFlag:: flag_array NUM_CITY_MAPS
@@ -2144,7 +2143,23 @@ wFossilItem:: db
 ; mon that will result from the item
 wFossilMon:: db
 
-	ds 2
+; Meltan WRAM entries.
+; Meltan uses a 3 unique variables for its item functionality.
+
+; This is for the Melmetal Evolution Item. 
+; If it reaches 40 (represented as 400), the player can evolve Meltan.
+; Once used, the count will reset.
+wCandyJarCount:: db
+
+; Used for Meltan implementation. Replaced unused Card Key function.
+; When byte is $01, Meltan has a chance to replace a Pokemon that appears.
+	; $00 - Not Active
+	; $01 - Active
+wMysteryBoxActive:: db
+
+; ClearVariablesOnEnterMap does everything I want, except when leaving battle, so this switches off that specific aspect.
+; This is achieved through some jank in engine\core.asm and engine\overworld\clear_variables.asm.
+wDontSwitchOffMysteryBoxYet:: db
 
 ; trainer classes start at OPP_ID_OFFSET
 wEnemyMonOrTrainerClass:: db
@@ -2152,9 +2167,7 @@ wEnemyMonOrTrainerClass:: db
 wPlayerJumpingYScreenCoordsIndex:: db
 
 wRivalStarter:: db
-
-	ds 1
-
+ds 1
 wPlayerStarter:: db
 
 ; sprite index of the boulder the player is trying to push
@@ -2177,12 +2190,6 @@ wDungeonWarpDestinationMap:: db
 ; which dungeon warp within the source map was used
 wWhichDungeonWarp:: db
 
-; Used for Meltan implementation. Replaced unused Card Key function.
-; When byte is $01, Meltan has a chance to replace a Pokemon that appears.
-	; $00 - Not Active
-	; $01 - Active
-wMysteryBoxActive:: db
-
 	ds 8
 
 ; bit 0: using Strength outside of battle