Umbris, Fear Manifest 
Legendary Creature — Nightmare Horror
Umbris gets +1/+1 for each card your opponents own in exile. Whenever Umbris or another Nightmare or Horror you control enters, target opponent exiles cards from the top of their library until they exile a land card.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL