Yu-Gi-Oh! Mermail Abyssgaios - Quarter Century Stampede

2 Level 7 WATER monsters
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.