Coercion

Target opponent reveals their hand. You choose a card from it. That player discards that card.

Armored Skaab

When Armored Skaab enters the battlefield, mill four cards.

Plague Stinger

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Markov Patrician

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Diplomatic Immunity

Enchant creature
Shroud (A permanent with shroud can't be the target of spells or abilities.)
Enchanted creature has shroud.

Black Cat

When Black Cat dies, target opponent discards a card at random.

Phyrexian Boon

Enchant creature
Enchanted creature gets +2/+1 as long as it's black. Otherwise, it gets -1/-2.

Swamp

Rishadan Cutpurse

When Rishadan Cutpurse enters the battlefield, each opponent sacrifices a permanent unless they pay {1}.

Burglar Rat

When Burglar Rat enters the battlefield, each opponent discards a card.

Whisper Agent

Flash
When Whisper Agent enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Bloodhunter Bat

Flying
When Bloodhunter Bat enters the battlefield, target player loses 2 life and you gain 2 life.

Dimir Infiltrator

Dimir Infiltrator can't be blocked.
Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Spinal Centipede

When Spinal Centipede dies, put a +1/+1 counter on target creature you control.

Island

Dimir Aqueduct

Dimir Aqueduct enters the battlefield tapped.
When Dimir Aqueduct enters the battlefield, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Distress

Target player reveals their hand. You choose a nonland card from it. That player discards that card.

Boomerang

Return target permanent to its owner's hand.

Gigadrowse

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Tap target permanent.

Marsh Gas

All creatures get -2/-0 until end of turn.

Compulsive Research

Target player draws three cards. Then that player discards two cards unless they discard a land card.

Festering Goblin

When Festering Goblin dies, target creature gets -1/-1 until end of turn.

Casting of Bones

Enchant creature
When enchanted creature dies, draw three cards, then discard one of them.

Crumbling Necropolis

Crumbling Necropolis enters the battlefield tapped.
{T}: Add {U}, {B}, or {R}.

Gryff Vanguard

Flying
When Gryff Vanguard enters the battlefield, draw a card.

Vampire Interloper

Watcher in the Mist

Flying
When Watcher in the Mist enters the battlefield, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Deprive

As an additional cost to cast this spell, return a land you control to its owner's hand.
Counter target spell.

Reality Acid

Enchant permanent
Vanishing 3 (This Aura enters the battlefield with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Reality Acid leaves the battlefield, enchanted permanent's controller sacrifices it.

Enfeeblement

Enchant creature (Target a creature as you cast this. This card enters the battlefield attached to that creature.)
Enchanted creature gets -2/-2.

Perplex

Counter target spell unless its controller discards their hand.
Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Abyssal Gatekeeper

When Abyssal Gatekeeper dies, each player sacrifices a creature.

Maximize Altitude

Target creature gets +1/+1 and gains flying until end of turn.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Capture Sphere

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
When Capture Sphere enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Nausea

All creatures get -1/-1 until end of turn.

Deranged Assistant

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)