Mermail Abyssgaios (UR) (RA04-EN065) [Quarter Century Stampede]

2 Level 7 WATER monsters<br>While this face-up card has Xyz Material, Level 5 or higher monsters cannot attack. Once per turn, during either player's turn: You can detach 1 Xyz Material from this card; negate the effects of all face-up monsters your opponent currently controls that have less ATK than this card, until the end of the turn.