Dreg Mangler

Haste
Scavenge (, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card’s power on target creature. Scavenge only as a sorcery.)

Abrupt Decay

This spell can’t be countered.
Destroy target nonland permanent with converted mana cost 3 or less.

Assassin

Whenever this creature deals combat damage to a player, that player loses the game.

Archon of the Triumvirate

Flying
Whenever Archon of the Triumvirate attacks, detain up to two target nonland permanents your opponents control. (Until your next turn, those permanents can’t attack or block and their activated abilities can’t be activated.)

Savage Surge

Target creature gets +2/+2 until end of turn. Untap that creature.

Jarad’s Orders

Search your library for up to two creature cards and reveal them. Put one into your hand and the other into your graveyard. Then shuffle your library.

Niv-Mizzet, the Firemind

Flying
Whenever you draw a card, Niv-Mizzet, the Firemind deals 1 damage to any target.
: Draw a card.

Jarad, Golgari Lich Lord

Jarad, Golgari Lich Lord gets +1/+1 for each creature card in your graveyard.
, Sacrifice another creature: Each opponent loses life equal to the sacrificed creature’s power.
Sacrifice a Swamp and a Forest: Return Jarad from your graveyard to your hand.

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Thundermaw Hellkite

Flying
Haste (This creature can attack and as soon as it comes under your control.)
When Thundermaw Hellkite enters the battlefield, it deals 1 damage to each creature with flying your opponents control. Tap those creatures.

Door to Nothingness

Door to Nothingness enters the battlefield tapped.
, , Sacrifice Door to Nothingness: Target player loses the game.

Galvanic Alchemist

Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. They remain paired for as long as you control both of them.)
As long as Galvanic Alchemist is paired with another creature, each of those creatures has “: Untap this creature.”

Hound of Griselbrand

Double strike
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner’s control with a +1/+1 counter on it.)

Gloomwidow

Reach
Gloomwidow can block only creatures with flying.

Crippling Chill

Tap target creature. It doesn’t untap during its controller’s next untap step.
Draw a card.

Treacherous Pit-Dweller

When Treacherous Pit-Dweller enters the battlefield from a graveyard, target opponent gains control of it.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner’s control with a +1/+1 counter on it.)

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Hellrider

Haste
Whenever a creature you control attacks, Hellrider deals 1 damage to the player or planeswalker it’s attacking.

Sightless Ghoul

Sightless Ghoul can’t block.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner’s control with a +1/+1 counter on it.)