Imoen, Wily Trickster

Legendary Creature — Human Rogue Wizard — {1}{U}{U}

Imoen, Wily Trickster can't be blocked. Whenever Imoen deals combat damage to a player, you may exile an instant or sorcery card from your graveyard. When you do, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.