Abzu, the Water God of Truth (2-042) [The War of Valhalla]

Resonator : Deity [Break] You may choose a card in your hand and put it face down on the bottom of your lifebreak area. [Flying] [Activate] Pay 0 : Look at the top card of your main deck. Then put that card on top or bottom of your main deck. This ability can only be activated once per turn.