Blighted Shaman

{T}, Sacrifice a Swamp: Target creature gets +1/+1 until end of turn.
{T}, Sacrifice a creature: Target creature gets +2/+2 until end of turn.

Opposition Agent

Flash
You control your opponents while they're searching their libraries.
While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

Bankrupt in Blood

As an additional cost to cast this spell, sacrifice two creatures.
Draw three cards.

Cuombajj Witches

{T}: Cuombajj Witches deals 1 damage to any target and 1 damage to any target of an opponent's choice.

Damnation

Destroy all creatures. They can't be regenerated.

Triangle of War

{2}, Sacrifice Triangle of War: Target creature you control fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Drudge Skeletons

{B}: Regenerate Drudge Skeletons. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Swamp

Crimson Roc

Flying
Whenever Crimson Roc blocks a creature without flying, Crimson Roc gets +1/+0 and gains first strike until end of turn.

Kukemssa Serpent

Kukemssa Serpent can't attack unless defending player controls an Island.
{U}, Sacrifice an Island: Target land an opponent controls becomes an Island until end of turn.
When you control no Islands, sacrifice Kukemssa Serpent.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Reaper of Sheoldred

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever a source deals damage to Reaper of Sheoldred, that source's controller gets a poison counter.

Ankh of Mishra

Whenever a land enters, Ankh of Mishra deals 2 damage to that land's controller.

Sedris, the Traitor King

Each creature card in your graveyard has unearth {2}{B}. ({2}{B}: Return the card to the battlefield. The creature gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Pit Scorpion

Whenever Pit Scorpion deals damage to a player, that player gets a poison counter. (A player with ten or more poison counters loses the game.)

Blight

Enchant land
When enchanted land becomes tapped, destroy it.

Varragoth, Bloodsky Sire

Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

Phyrexian Crusader

First strike, protection from red and from white
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Ob Nixilis, Unshackled

Flying, trample
Whenever an opponent searches their library, that player sacrifices a creature of their choice and loses 10 life.
Whenever another creature dies, put a +1/+1 counter on Ob Nixilis, Unshackled.

Blood for Bones

As an additional cost to cast this spell, sacrifice a creature.
Return a creature card from your graveyard to the battlefield, then return another creature card from your graveyard to your hand.

Kaervek's Hex

Kaervek's Hex deals 1 damage to each nonblack creature and an additional 1 damage to each green creature.

Trailblazer's Boots

Equipped creature has nonbasic landwalk. (It can't be blocked as long as defending player controls a nonbasic land.)
Equip {2}

Barreling Attack

Target creature gains trample until end of turn. When that creature becomes blocked this turn, it gets +1/+1 until end of turn for each creature blocking it.

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Taniwha

Trample
Phasing (This phases in or out before you untap during each of your untap steps. While it's phased out, it's treated as though it doesn't exist.)
At the beginning of your upkeep, all lands you control phase out. (They phase in before you untap during your next untap step.)

Odylic Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Whenever Odylic Wraith deals damage to a player, that player discards a card.

Shrieking Drake

Flying
When Shrieking Drake enters, return a creature you control to its owner's hand.

Sea Serpent

Sea Serpent can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Sea Serpent.

Restless Dead

Skull Catapult

{1}, {T}, Sacrifice a creature: Skull Catapult deals 2 damage to any target.

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Horrible Hordes

Rampage 1 (Whenever this creature becomes blocked, it gets +1/+1 until end of turn for each creature blocking it beyond the first.)

Feast of Succession

All creatures get -4/-4 until end of turn. You become the monarch.

Tainted Strike

Target creature gets +1/+0 and gains infect until end of turn. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)