You can Ritual Summon this card with A.I. s Ritual . If this card is Ritual Summoned: You can return all monsters your opponent control with 2300 or less ATK to the hand. You can target 1 face-up monster your opponent controls; return all Link Monsters from your GY to the Extra Deck, and if you do, change that targeted monster s ATK to 0. You can only use this effect of Water Leviathan @Ignister once per turn. Once per battle, during damage calculation, if this card battles an opponent s monster (Quick Effect): You can halve the ATK of that opponent s monster, during that damage calculation only.