Swamp

Akroan Conscriptor

Heroic — Whenever you cast a spell that targets Akroan Conscriptor, gain control of another target creature until end of turn. Untap that creature. It gains haste until end of turn.

Endless Obedience

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Put target creature card from a graveyard onto the battlefield under your control.

Child of Night

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Sengir Vampire

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever a creature dealt damage by Sengir Vampire this turn dies, put a +1/+1 counter on Sengir Vampire.

Sign in Blood

Target player draws two cards and loses 2 life.

Accursed Spirit

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Crippling Blight

Enchant creature
Enchanted creature gets -1/-1 and can't block.

Rakdos Drake

Flying
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Borderland Marauder

Whenever Borderland Marauder attacks, it gets +2/+0 until end of turn.

Fall of the Hammer

Target creature you control deals damage equal to its power to another target creature.

Wildfire Cerberus

{5}{R}{R}: Monstrosity 1. (If this creature isn't monstrous, put a +1/+1 counter on it and it becomes monstrous.)
When Wildfire Cerberus becomes monstrous, it deals 2 damage to each opponent and each creature they control.

Crowd's Favor

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Target creature gets +1/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Squelching Leeches

Squelching Leeches's power and toughness are each equal to the number of Swamps you control.

Warchanter of Mogis

Inspired — Whenever Warchanter of Mogis becomes untapped, target creature you control gains intimidate until end of turn. (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Lightning Strike

Lightning Strike deals 3 damage to any target.

Magma Jet

Magma Jet deals 2 damage to any target. Scry 2.

Searing Blood

Searing Blood deals 2 damage to target creature. When that creature dies this turn, Searing Blood deals 3 damage to the creature's controller.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Trouble

Trouble deals damage to target player equal to the number of cards in that player's hand.
Fuse (You may cast one or both halves of this card from your hand.)

Toil

Target player draws two cards and loses 2 life.
Fuse (You may cast one or both halves of this card from your hand.)

Toil // Trouble

Mind Rot

Furnace Whelp

Flying
{R}: Furnace Whelp gets +1/+0 until end of turn.

Typhoid Rats

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Scouring Sands

Scouring Sands deals 1 damage to each creature your opponents control. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Stab Wound

Enchant creature
Enchanted creature gets -2/-2.
At the beginning of the upkeep of enchanted creature's controller, that player loses 2 life.

Minotaur Skullcleaver

Haste
When Minotaur Skullcleaver enters, it gets +2/+0 until end of turn.

Covenant of Blood

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Covenant of Blood deals 4 damage to any target and you gain 4 life.

Mountain

Pharika's Cure

Pharika's Cure deals 2 damage to target creature and you gain 2 life.

Magma Spray

Magma Spray deals 2 damage to target creature. If that creature would die this turn, exile it instead.