Mystical Stalker

Limbo {u} (You may exile this card from your hand for its limbo cost at any time. You may return it from exile to your hand anytime for its limbo cost.)
When Mystical Stalker leaves the battlefield, return all exiled cards with Limbo to their owners' hands.

Some say it's allure, and others say it's fear, but something about that beast makes things that were once thought lost forever, return.