Lightning Reaver

Haste; fear (This creature can't be blocked except by artifact creatures and/or black creatures.) Whenever this creature deals combat damage to a player, put a charge counter on it. At the beginning of your end step, this creature deals damage equal to the number of charge counters on it to each opponent.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6o692j3kb1pb1hl0yzfzb7.