[+1]: Create a 1/1 black Vampire creature token with lifelink. [-2]: You get an emblem with "Creatures you control get +1/+0." [-6]: Destroy up to three target creatures and/or other planeswalkers. Return each card put into a graveyard this way to the battlefield under your control.
When Mesmeric Fiend enters the battlefield, target opponent reveals their hand and you choose a nonland card from it. Exile that card. When Mesmeric Fiend leaves the battlefield, return the exiled card to its owner's hand.