Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Sword of the Meek

Equipped creature gets +1/+2.
Equip {2}
Whenever a 1/1 creature enters under your control, you may return Sword of the Meek from your graveyard to the battlefield, then attach it to that creature.

The Rack

As The Rack enters, choose an opponent.
At the beginning of the chosen player's upkeep, The Rack deals X damage to that player, where X is 3 minus the number of cards in their hand.

Mindstab Thrull

Whenever Mindstab Thrull attacks and isn't blocked, you may sacrifice it. If you do, defending player discards three cards.

Mind Rot

Blasting Station

{T}, Sacrifice a creature: Blasting Station deals 1 damage to any target.
Whenever a creature enters, you may untap Blasting Station.

Thopter Foundry

{1}, Sacrifice a nontoken artifact: Create a 1/1 blue Thopter artifact creature token with flying. You gain 1 life.

Psychic Strike

Counter target spell. Its controller mills two cards.

Recall

Discard X cards, then return a card from your graveyard to your hand for each card discarded this way. Exile Recall.

Horrifying Revelation

Target player discards a card, then mills a card.

Mind Twist

Target player discards X cards at random.

Mind Ravel

Target player discards a card.
Draw a card at the beginning of the next turn's upkeep.

Rag Man

{B}{B}{B}, {T}: Target opponent reveals their hand and discards a creature card at random. Activate only during your turn.

Zuran Enchanter

{2}{B}, {T}: Target player discards a card. Activate only during your turn.

Mind Warp

Look at target player's hand and choose X cards from it. That player discards those cards.

Hymn to Tourach

Target player discards two cards at random.

Mask of Riddles

Equipped creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
Whenever equipped creature deals combat damage to a player, you may draw a card.
Equip {2}

Geth's Grimoire

Whenever an opponent discards a card, you may draw a card.

Locust Miser

Each opponent's maximum hand size is reduced by two.

Island

Abyssal Specter

Flying
Whenever Abyssal Specter deals damage to a player, that player discards a card.

Dimir Guildgate

This land enters tapped.
{T}: Add {U} or {B}.

Dark Ritual

Will-o'-the-Wisp

Flying (This creature can't be blocked except by creatures with flying or reach.)
{B}: Regenerate Will-o'-the-Wisp. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Cloak of Confusion

Enchant creature you control
Whenever enchanted creature attacks and isn't blocked, you may have it assign no combat damage this turn. If you do, defending player discards a card at random.

Counterspell

Megrim

Whenever an opponent discards a card, Megrim deals 2 damage to that player.

Spell Blast

Counter target spell with mana value X. (For example, if that spell's mana cost is {3}{U}{U}, X is 5.)

Hypnotic Specter

Flying
Whenever Hypnotic Specter deals damage to an opponent, that player discards a card at random.