msem-instigator

Disgraced 2 (This enters with two -1/-1 counters. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Whenever Madame Deficit attacks, you may tap target creature.

Flying, lifelink
Other creatures you control have lifelink.

Lifelink
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on United Guardian. It loses this ability and gains “Whenever United Guardian attacks, create two 1/1 blue Elemental creature tokens with flying that are tapped and attacking.”

When Abberant Frostbringer enters, tap up to one target creature. If you do, put two stun counters on that creature. (If a permanent with a stun counter would become untapped, remove one from it instead.)

When Benthic Tidebreaker enters, reveal the top card of each player's library and exile one of those cards. You may play that card for as long as it remains exiled, and you may spend blue mana as though it were mana of any color to cast it.
Evoke {1}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Flying
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Enlightened Guardian. It loses this ability and gains “Whenever this creature attacks, draw two cards.”

When Inner-Eye Obscurist enters, return each other creature that isn't in Inner-Eye Obscurist's pack to their owners' hand. (Two or more creatures you control with equal power are in a pack.)

Enchant creature
Embody (Enchanted creature is a copy of this card except for its types.)
As long as Legend of the Wayward is tapped, you may look at and play the top card of your library.

Whenever Marshback Knights becomes the target of a spell or ability an opponent controls, counter it unless they pay {3}.
{1}{U}: Marshback Knights gains flying until end of turn.

Flying
Whenever Notorious Windraider attacks, other attacking Pirates and Rogues you control gain flying until end of turn.

{3}{U}, Reveal this card from your hand, Return an unblocked attacking creature you control to its owner's hand: Put Phasewalker Rake from your hand onto the battlefield tapped and attacking. If you returned a Pirate or Rogue this way, draw a card.

Vigilance
When Skaab Grappler enters, you may exile two creature cards from your graveyard. When you do, return another target creature to its owner's hand.

Whenever Wakeborne Kraken or another Kraken, Leviathan, Octopus, or Serpent you control enters, you may return target creature an opponent controls to its owner's hand.
Whenever a creature an opponent controls leaves the battlefield, if it didn't die, draw a card.

Menace
Whenever Algrin's Legacy becomes the target of a spell an opponent controls, that spell's controller loses 5 life unless they discard a card.

Blighted Unicorn can't block.
Ride {3}{B} ({3}{B}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

When Bloodpact Collector enters, destroy target creature an opponent controls that was dealt damage this turn or has a -1/-1 counter on it.

Flying, deathtouch, lifelink
Ride {1}{B} ({1}{B}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)
You may activate Bonescourge Kazadrak's ride ability from your graveyard by sacrificing a creature in addition to paying its other costs.

Whenever Cavern Monstrosity attacks, exile the bottom card of your library. You gain life equal to its mana value.

Doomsday Horde enters tapped unless it was foreshadowed.
When Doomsday Horde dies, search your library for a card, put it into your hand, then shuffle.
Foreshadow {3}{B}{B}{B} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

Bloodprice {2}{B} (You may cast this card by sacrificing a creature and paying its bloodprice.)

Flying, trample
When Greedstoker Demon enters, you lose X life and create X Treasure tokens, where X is your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
You can't sacrifice more than one Treasure each turn.

Menace
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Jaded Guardian. It loses this ability and gains “Whenever this creature attacks, defending player sacrifices two permanents.”

Enchant creature
Embody (Enchanted creature is a copy of this card except for its types.)
As long as Legend of the Weary is tapped, creatures you don't control get -1/-1.

When Manglehorn Hunter enters, draw a card and you lose 1 life.

Menace
Crew 3
You may exile two creature cards from your graveyard rather than pay Phantom Walker's crew cost.