- Returning Arianne to hand is a cost, and occurs even if her ability is canceled.
- When a card leaves play, it returns to it's owner's out-of-play area, so if an opponent takes control of your Arianne, she will return to your hand if your opponent uses her ability.
Can a "return to hand" be saved? In other words, does returning 1 copy satisfy the ability? (Especially with Ghaston Grey (cannot be saved) in mind) — Xavaerys Targaryen 1
@Xavaerys Costs cannot be saved, so you have to actually return Arianne to hand to satisfy the cost. However, your opponent could use a dupe to save the target from leaving play. — scantrell24 3150