R.B. Next Phase (DOOD-EN096) - Doom of Dimensions 1st Edition

When your opponent activates a monster effect, while you control an "R.B." monster: Destroy 1 monster you control, and if you do, negate the activation, and if you do that, destroy that card, then gain 2000 LP. You can only activate 1 "R.B. Next Phase" per turn.