Gadarla, the Mystery Dust Kaiju (SDBT-EN009) [Structure Deck: Beware of Traptrix]

You can Special Summon this card (from your hand) to your opponent's side of the field in Attack Position, by Tributing 1 monster they control. If your opponent controls a "Kaiju" monster, you can Special Summon this card (from your hand) in Attack Position. You can only control 1 "Kaiju" monster. Once per turn, during either player's turn: You can remove 3 Kaiju Counters from anywhere on the field; the ATK and DEF of all other monsters on the field become halved.