Sire of Insanity

Master of Cruelties

Creature — Demon (1/4)

First strike, deathtouch
Master of Cruelties can only attack alone.
Whenever Master of Cruelties attacks a player and isn't blocked, that player's life total becomes 1. Master of Cruelties assigns no combat damage this combat.

Boros Battleshaper

Creature — Minotaur Soldier (5/5)

At the beginning of each combat, up to one target creature attacks or blocks this combat if able and up to one target creature can't attack or block this combat.

Species Gorger

Creature — Frog Beast (6/6)

At the beginning of your upkeep, return a creature you control to its owner's hand.

Aetherling

Creature — Shapeshifter (4/5)

: Exile Aetherling. Return it to the battlefield under its owner's control at the beginning of the next end step.
: Aetherling can't be blocked this turn.
: Aetherling gets +1/-1 until end of turn.
: Aetherling gets -1/+1 until end of turn.

Ruric Thar, the Unbowed

Legendary Creature — Ogre Warrior (6/6)

Vigilance, reach
Ruric Thar, the Unbowed attacks each combat if able.
Whenever a player casts a noncreature spell, Ruric Thar deals 6 damage to that player.

Progenitor Mimic

Creature — Shapeshifter (0/0)

You may have Progenitor Mimic enter the battlefield as a copy of any creature on the battlefield, except it has "At the beginning of your upkeep, if this creature isn't a token, create a token that's a copy of this creature."

Mirko Vosk, Mind Drinker

Legendary Creature — Vampire (2/4)

Flying
Whenever Mirko Vosk, Mind Drinker deals combat damage to a player, that player reveals cards from the top of their library until they reveal four land cards, then puts those cards into their graveyard.

Lavinia of the Tenth

Legendary Creature — Human Soldier (4/4)

Protection from red
When Lavinia of the Tenth enters the battlefield, detain each nonland permanent your opponents control with mana value 4 or less. (Until your next turn, those permanents can't attack or block and their activated abilities can't be activated.)

Zhur-Taa Ancient

Creature — Beast (7/5)

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Blaze Commando

Creature — Minotaur Soldier (5/3)

Whenever an instant or sorcery spell you control deals damage, create two 1/1 red and white Soldier creature tokens with haste.

Blood Baron of Vizkopa

Creature — Vampire (4/4)

Lifelink, protection from white and from black
As long as you have 30 or more life and an opponent has 10 or less life, Blood Baron of Vizkopa gets +6/+6 and has flying.

Haunter of Nightveil

Creature — Spirit (3/4)

Creatures your opponents control get -1/-0.

Korozda Gorgon

Creature — Gorgon (2/5)

Deathtouch
, Remove a +1/+1 counter from a creature you control: Target creature gets -1/-1 until end of turn.

Maw of the Obzedat

Creature — Thrull (3/3)

Sacrifice a creature: Creatures you control get +1/+1 until end of turn.

Melek, Izzet Paragon

Legendary Creature — Weird Wizard (2/4)

Play with the top card of your library revealed.
You may cast instant and sorcery spells from the top of your library.
Whenever you cast an instant or sorcery spell from your library, copy it. You may choose new targets for the copy.

Scab-Clan Giant

Creature — Giant Warrior (4/5)

When Scab-Clan Giant enters the battlefield, it fights target creature an opponent controls chosen at random.

Teysa, Envoy of Ghosts

Legendary Creature — Human Advisor (4/4)

Vigilance, protection from creatures
Whenever a creature deals combat damage to you, destroy that creature. Create a 1/1 white and black Spirit creature token with flying.

Pontiff of Blight

Creature — Zombie Cleric (2/7)

Extort (Whenever you cast a spell, you may pay . If you do, each opponent loses 1 life and you gain that much life.)
Other creatures you control have extort. (If a creature has multiple instances of extort, each triggers separately.)

Armored Wolf-Rider

Creature — Elf Knight (4/6)

Emmara Tandris

Legendary Creature — Elf Shaman (5/7)

Prevent all damage that would be dealt to creature tokens you control.