Core Blast

You can only activate this card's effect while you control a face-up "Koa'ki Meiru" monster. Once per turn, during your Standby Phase, if your opponent controls more monsters than you do, you can destroy a number of cards your opponent controls so that your opponent will control the same number of cards as you control

monsters.

From Yu-Gi-Oh! Trading Card Game.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6nnapu16yesb1iftqcs1dq.