Cast Heartless Act by paying ({1} magic symbol) ({B} magic symbol) , removing up to three oil counters from Archfiend of the Dross.
Cast Donate by paying ({2} magic symbol) ({U} magic symbol) , causing you to give control of Archfiend of the Dross to an opponent.
At the beginning of the opponent's next upkeep, Archfiend of the Dross triggers, causing the opponent to remove an oil counter from it and lose the game.
Results
Target opponent loses the game at the beginning of their next upkeep.