Fiend Hunter

When Fiend Hunter enters, you may exile another target creature.
When Fiend Hunter leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Innistrad Remastered

"What roads would any dare to tread if the Dúnedain were all gone into the grave?"
—Aragorn

Tales of Middle-earth Commander

When Fiend Hunter enters the battlefield, you may exile another target creature.
When Fiend Hunter leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Shadows of the Past

The List

If Fiend Hunter leaves the battlefield before its first ability has resolved, its second ability will trigger and do nothing. Then its first ability will resolve and exile the target creature indefinitely. This is different from abilities on other cards that exile a permanent "until" something happens.

If a token is exiled this way, it won't return to the battlefield.

In a multiplayer game, if you lose the game, the creature exiled with Fiend Hunter remains exiled indefinitely. This is also different from abilities on other cards that exile a permanent "until" something happens.

Once the exiled creature returns, it's considered a new object with no relation to the object that it was. Auras attached to the exiled creature will be put into their owners' graveyards. Equipment attached to the exiled creature will become unattached and remain on the battlefield. Any counters on the exiled creature will cease to exist.