If you control an Xyz Monster that has an Xyz Monster as material: Declare 1 monster Attribute on the field; destroy all monsters on the field with that Attribute, except monsters equipped with an Equip Spell. You can banish this card from your GY and detach 1 material from a monster you control; Special Summon 1 Fish, Sea Serpent, or Aqua monster from your GY to either field. You can only use 1 "Xyz Poseidon Splash" effect per turn, and only once that turn.