Ring of Destruction (Platinum Secret Rare) (RA04-EN119) [Quarter Century Stampede]

During your opponent's turn: Target 1 face-up monster your opponent controls whose ATK is less than or equal to their LP; destroy that face-up monster, and if you do, take damage equal to its original ATK, then inflict damage to your opponent, equal to the damage you took. You can only activate 1 "Ring of Destruction" per turn.