msem-instigator

Exile up to one target artifact or enchantment.
Coalesce {5}{G} (You may cast this from your graveyard for {5}{G}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Bulwark — When Tharanos' Legion enters, draw a card for each creature you control with toughness 4 or greater.

Vigilance, reach
When Winter Widow enters, you may destroy target creature with flying.

Pressure—{4}{U}{B}, Sacrifice two creatures. (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Whenever Oryxyth enters or attacks, create an X/X black Horror creature token, where X is the number of cards in your graveyard.
{U}{B}, Sacrifice another creature: Gain control of target creature with power less than the sacrificed creature's power.

Flying, deathtouch
Whenever Yaran enters or attacks, target opponent may pay 3 life. If that player doesn't, they choose a nonland permanent they control. Tap that permanent. You gain control of it. (This effect doesn't end.)

Play with the top card of your library revealed.
You may cast creature spells from the top of your library. You may cast Centaur spells this way without paying their mana costs.

Wildfire Elemental has frenzy 4 as long as you control no other creatures. (Whenever this creature attacks and isn't blocked, it gets +4/+0 until end of turn.)
Wildfire Elemental has frenzy 4 as long as you have no cards in hand.

Mill five cards. You may choose up to two nonland cards with mana value 2 or less milled this way. You may cast one without paying its mana cost. Put the rest into your hand.
Coalesce {6}{G}{W} (You may cast this from your graveyard for {6}{G}{W}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Flying, vigilance

Hexproof

Whenever Penny and Pete attacks, gain control of up to one target noncreature permanent and up to one target creature until end of turn. Untap the noncreature permanent, then tap the creature. It's attacking.

Vigilance
Avatar of Utsenchep can block any number of creatures.
All creatures able to block Avatar of Utsenchep do so.

Indestructible
As long as your devotion to white is less than five, Heliod isn't a creature.
If an effect would create one or more kinds of tokens under your control, it creates an additional token of each kind.
{3}{W}: Put a +1/+1 counter on each other creature you control. Activate only as a sorcery.

Ward {4}
{4}{U}: Cyclesmith Oracle can't be blocked until end of turn. This ability costs {X} less to activate, where X is the number of card types among cards in your graveyard.

Flying
At the beginning of your upkeep, if it isn't an extra turn, put a sage counter on Magistrate of Eras.
Remove five sage counters from Magistrate of Eras: Take an extra turn after this one.

Target player discards a card and gets a poison counter.
Coalesce {4}{B}{B} (You may cast this from your graveyard for {4}{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.)

Flying, vigilance
At the beginning of your end step, return up to one target creature card from your graveyard to the battlefield. If a creature isn't returned this way, create a 4/4 Elemental creature token that's all colors.

Hexproof, crew 6 (Tap any number of creatures you control with total power 6 or greater: This Vehicle becomes an artifact creature until end of turn.)
Whenever The Ark Project deals combat damage to an opponent or planeswalker, gain control of target creature until The Ark Project leaves the battlefield.
Whenever The Ark Project blocks a creature, gain control of that creature.

Flying
You pay {0} to cast your first spell each turn rather than its mana cost. If you cast a spell with {X} in its mana cost this way, X is 8.

{G}{U}: Glacier Tortoise gets +5/-5 until end of turn. Activate only once each turn.

When Almgrove Performer enters, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — You gain 3 life.

When Banishing Initiate enters, you may exile target nonland permanent you don't control until Banishing Initiate leaves the battlefield.
At the beginning of your end step, sacrifice Banishing Initiate if a card exiled with it has mana value 3 or greater.

Battalion — Whenever Barbaric Ambusher and at least two other creatures attack, you may tap target creature.

Whenever Bourasan Street Watch attacks, you may pay {W}. If you do, Bourasan Street Watch gains indestructible until end of turn.

Bristling Skoki has first strike as long as it's attacking.
Whenever Bristling Skoki blocks a creature, you may have it deal damage equal to its toughness to that creature.

Whenever another creature you control enters, you gain 1 life.