3 Level 7 monsters Once per turn, you can also Xyz Summon "Poseidra Abyss, the Atlantean Dragon Lord" by using 1 "Atlantean" or "Mermail" Xyz Monster you control.

(Transfer its materials to this card.) Once per turn: You can detach 2 materials from this card, then send 1 WATER monster from your hand or Deck to the GY; return up to 3 cards your opponent controls to the hand.