Ravenloft Adventurer (Commander Legends: Battle for Baldur's Gate)

Creature Ñ Human Rogue Assassin - When this creature enters, you take the initiative.
If a creature an opponent controls would die, instead exile it and put a hit counter on it.
Whenever this creature attacks, if you've completed a dungeon, defending player loses 1 life for each card they own in exile with a hit counter on it.