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

Flying At the beginning of each combat, any opponent may sacrifice a creature of their choice. If a player does, tap this creature and put a +1/+1 counter on it.

When Kroxa enters, sacrifice it unless it escaped. Whenever Kroxa enters or attacks, each opponent discards a card, then each opponent who didn't discard a nonland card this way loses 3 life. Escape—{B}{B}{R}{R}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Trample Champion an Elemental (When this enters, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)

Trample When this creature enters, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

As an additional cost to cast this spell, discard two cards. Draw three cards.

Draw two cards, then discard two cards. Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.