Grim/Ark, Chaos Undivided

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token that's a copy of this creature that's tapped and attacking that player or a planeswalker they control. If one or more tokens are created this way, exile the tokens at end of combat.)
Whenever Grim/Ark, Chaos Undivided deals
combat damage to a player, that player must sacrifice an artifact