u/SupremeOssian

Had this situation arise in a game and we were unsure of what was supposed to happen.

Player A controls an Avacyn, Angel of Horror that is owned by player B. Player C casts The Reaper, King No More putting a -1/-1 counter on Avacyn and then kills it with another spell. Avacyn would return to player B’s graveyard but then player C chooses to put it under their control. At the beginning of the next end step, does player C keep Avacyn or is there a delayed trigger that would return it to player A’s battlefield because they were the controller when it died?