Fire Lord Ozai — Avatar: The Last Airbender Eternal #104

Whenever Fire Lord Ozai attacks, you may sacrifice another creature. If you do, add an amount of equal to the sacrificed creature's power. Until end of combat, you don't lose this mana as steps end.

: Exile the top card of each opponent's library. Until end of turn, you may play one of those cards without paying its mana cost.