Mesmeric Fiend
Creature — Nightmare Horror
When this creature enters, target opponent reveals their hand and you choose a nonland card from it. Exile that card.
When this creature leaves the battlefield, return the exiled card to its owner's hand.
Dana Knutson
The List (PLST)
• #TOR-69Rulings
If Mesmeric Fiend 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 a nonland card from the target opponent's hand indefinitely.
(wotc • 2018-03-16)
Rulings
If Mesmeric Fiend 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 a nonland card from the target opponent's hand indefinitely.
(wotc • 2018-03-16)