msem-instigator

Flash
When Cocky Bladesinger enters, it gains first strike, lifelink, and haste until end of turn.

Haste
Coldhearted Explorer can't block.

Haste
When Collapsing Star Viper enters, you may tap target permanent with mana value X or less.
At the beginning of your upkeep, return Collapsing Star Viper to its owner's hand.

{R}: You may put a Rebel creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Whenever one or more creatures you control with counters on them attack, draw a card.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever a marked creature dies, you lose 1 life and you draw a card.

Spells you cast from exile cost {1} less to cast.

When Condemned Cavalier enters, create a white and black Aura Curse enchantment token named Profane March attached to target player. The token has enchant player and “Whenever a creature enchanted player controls attacks, that player loses 1 life and defending player gains 1 life.”

Other Knight creatures you control get +1/+1.

Flying
At end of combat on your turn, untap all creatures you control with power greater than their base power.

Exile up to one target creature.
Coalesce {5}{B}{B} (You may cast this from your graveyard for {5}{B}{B}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Whenever Consign to Oblivion deals damage to a permanent, exile that permanent.

Create two 1/2 blue Bird creature tokens with flying.
Coalesce {5}{U}{U} (You may cast this from your graveyard for {5}{U}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Trample
When Contentious Yak enters, another target creature you control gets +1/+1 and gains trample until end of turn.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Cycling {U} ({U}, Discard this card: Draw a card.)

Vigilance, trample
Whenever you draw your second card each turn, put a +1/+1 counter on Coralblade Cohort.
Cycling {G} ({G}, Discard this card: Draw a card.)

{3}{W}: Tap target creature. Activate only during your turn.

Concord — When Coralight Communer enters, if there are four or more card types among permanents you control, draw a card.

Whenever another Zombie you control enters, you may pay {1}{B}. If you do, exile target creature card from a graveyard. You gain life equal to its toughness.

Whenever another Zombie or Demon creature you control enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Menace
Sacrifice another creature: Corpulent Gibberer deals 1 damage to any target.
Evoke {1}{R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Corsair Sellsword can't block.
Whenever you foretell a card or cast a foretold spell, you may return Corsair Sellsword from your graveyard to your hand.

Reach
Improve {1}{G/W} ({1}{G/W}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on that creature instead.

When Cosmonaut Pioneer enters or leaves the battlefield, choose one—
• Scry 1, then draw a card.
• Create a 3/3 green Alien creature token with trample.
• You gain 5 life.

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Flying
{2}{W}: Prevent all damage that would be dealt to and dealt by creatures with counters on them this turn.

Sacrifice a creature: Each opponent loses 1 life and you gain 1 life.
Sacrifice two creatures: Draw a card.
Sacrifice three creatures: Exile target creature or planeswalker.