Berserking

Once per turn, during your Main Phase or your opponent's Battle Phase, you can select 2 face-up Beast-Type monsters on the field. Until the end of turn, 1 of the selected monsters loses half its ATK, and the other monster gains an equal amount of ATK.

From Yu-Gi-Oh! Trading Card Game.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6nmiec0ilesb1ij4lgtxs4.