msem-instigator

Search your library for a card. You may cast it without paying its mana cost if it's a green creature or Revelation spell with mana value X or less. Then shuffle.
Coalesce {X}{X}{G}{G}{G}{G} (You may cast this from your graveyard for {X}{X}{G}{G}{G}{G}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Haste
{6}{R}: Diasune Immolator deals 4 damage to target player or planeswalker.

({T}: Add {G} or {U}.)
Whenever Shifting Glade becomes tapped, you lose 1 life unless you control two or more basic lands.

{T}: Add {C}.
{7}, {T}: Create a 2/2 colorless Spirit creature token.

Flying, haste
Miyoga Firebird attacks each combat if able.
Whenever you cast your third instant or sorcery spell this turn, you may return Miyoga Firebird from your graveyard to the battlefield.

At the beginning of each player's upkeep, that player may pay {2} or 2 life. If they don't, they return a permanent they control to its owner's hand.

Flying
Whenever you gain life, target creature an opponent controls gets -1/-1 until end of turn.

Target creature gets -2/-2 until end of turn.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, return up to one target enchantment card from your graveyard to your hand.

Pay 2 life: Lifecraft Aberration gains indestructible until end of turn.
Pay 3 life: Lifecraft Aberration gets +1/+1 until end of turn.

When Ethersketch Blueprints enters, create a 1/1 blue Thopter artifact creature token with flying.
{2}, Sacrifice Ethersketch Blueprints: Draw a card.
Monument {5}{B}{B} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)
Ascend {4}{W} ({4}{W}: Exile this permanent, then return it to the battlefield transformed. Ascend only as a sorcery.)

Create two 2/2 white Griffin creature tokens with flying. If you control a legendary creature, create three of those tokens instead.

When Seafloor Cache enters and when you sacrifice it, create a Treasure token.
{1}{R}, Sacrifice Seafloor Cache: Draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Lifelink
Instant and sorcery spells you control have lifelink.
{2}{R}{W}: Copy target instant or sorcery spell. You may choose new targets for the copy.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever Loyal Firestarter attacks, you may cast an instant or sorcery spell from your hand with mana value less than or equal to Loyal Firestarter's power without paying its mana cost.

Radiant Vistas enters tapped.
{T}: Add {W} or {U}.
{W}{U}, {T}, Sacrifice Radiant Vistas: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

Ash Freebooter has first strike as long as it's attacking.
When Ash Freebooter enters, you may discard a card. If you do, draw a card.

Equipped creature has vigilance and can block an additional creature each combat.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Menace
Whenever Searing Sandwurm is dealt damage, it deals that much damage to target player or planeswalker.

Haste
{R}{R}{R}, Discard your hand, Sacrifice Crimson Knight: Draw three cards.

{T}: Add {C}.
{1}, {T}: Add two mana of different colors. Activate only if you control five or more lands.

Prowess
Gusma's Emissary gets +1/+1 as long as you control a black or green permanent.

Flying, lifelink
When Archdemon Shilgengar enters, exile all land cards from your graveyard, exchange your graveyard and library, then shuffle your library.
You can only cast spells by paying life equal to their mana value rather than paying their mana cost.

Whenever an opponent discards a card, you may draw a card.

S-19 Long Jacket has first strike as long as it's attacking.
S-19 Long Jacket has lifelink as long as it's blocking.

Destroy target creature.