Ashiok, Sculptor of Fears

+2: Draw a card. Each player mills two cards.
−5: Put target creature card from a graveyard onto the battlefield under your control.
−11: Gain control of all creatures target opponent controls.

Scare Tactics

Creatures you control get +1/+0 until end of turn.

Umbris, Fear Manifest

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.

Fear

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)

Worst Fears

You control target player during that player's next turn. Exile Worst Fears. (You see all cards that player could see and make all decisions for the player.)

Face of Fear

{2}{B}, Discard a card: This creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

Abyssal Nocturnus

Whenever an opponent discards a card, this creature gets +2/+2 and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Frightcrawler

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Threshold — As long as seven or more cards are in your graveyard, this creature gets +2/+2 and can't block.

Crippling Fear

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

Fill with Fright

Target player discards two cards. Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)