Acererak the Archlich

When Acererak the Archlich enters the
battlefield, if you haven't completed Tomb of
Annihilation, return Acererak the Archlich
to its owner's hand and venture into the
dungeon.
Whenever Acererak the Archlich attacks, for
each opponent, you create a 2/2 black Zombie
creature token unless that player sacrifices a
creature.