msem-instigator

Destroy target noncreature, nonland permanent. (Destroying a battle doesn't remove counters from it.)
Flashback {3}{W}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

(Transform this if it's not attached to a creature. Pay {4}{G} as a sorcery to unattach it.)
Enchant creature you control
Herdstrider's rider gets +1/+1 for each land you control and has trample.
Whenever Herdstrider's rider attacks, create an X/X green Elephant creature token with trample that's tapped and attacking, where X is that creature's power. Exile that token at the end of combat.

Flying
{1}{W/U}{W/U}: Creatures you control gain flying until end of turn if another creature you control has flying. The same is true for first strike, double strike, deathtouch, haste, indestructible, lifelink, menace, reach, trample, and vigilance.

Enchant creature
You control enchanted creature.
At the beginning of your upkeep, enchanted creature's owner may have you draw three cards. If they do, sacrifice Take For Ransom.

Flying

When Renegade Servitor enters, you gain 2 life and scry 1.

This spell can't be countered.
Survivor spells you cast can't be countered.
Whenever a nontoken Survivor you control enters, create a tapped 1/1 Survivor creature token that's all colors.

Destroy target nonland permanent with mana value 3 or less. (Then exile this card. You may cast Irbek later from exile.)

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Mindscreech Drake deals combat damage to a player, that player mills three cards.

{T}, Pay 1 life: Add {R} or {W}.
{2}, {T}, Sacrifice Tenement Alley and another permanent: Draw a card. Activate only during your turn.

Investigate, then target creature gets -1/-1 until end of turn for each Clue you control. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)
Discard a card: Abominable Mongrel gets +1/+1 and becomes the color of your choice until end of turn.

Whenever Cattish Bluestocking deals combat damage to a player, draw a card.
Attain {4}{U} ({4}{U}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Whenever a creature enters, it deals damage equal to its power to any target of its controller's choice.
When Interplanar Raid enters, you may aetherize target creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)

This spell costs {1} less to cast for each card type among cards in your graveyard.
Trample

When Atrocity of Flesh enters, destroy target nonland permanent.
When Atrocity of Flesh dies, you may exile it. If you do, return target card from your graveyard to your hand.

Return target nonland card from your graveyard to your hand. (Cast a copy of this spell once while this creature is on the battlefield.)

{R}: Igniting Lavaling gets +1/+0 until end of turn.
{4}{R}, Sacrifice Igniting Lavaling: It deals 3 damage to any target.

Whenever you cast an instant or sorcery spell, look at the bottom card of your library. You may manifest it. If you don't, put it into your hand. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Each player sacrifices three lands. Torment each player three times. (To torment a player, they lose 3 life unless they discard a card or sacrifice a nonland permanent.)

When Sihari's Groundblazer enters, create a red Aura enchantment token named Searing Crags attached to target land. The token has enchant land, “Enchanted land's name is Charred Causeway” and “Enchanted land has {T}: This land deals 1 damage to each opponent.”

Enchant opponent
Creatures enchanted player control lose hexproof and indestructible and can't have or gain hexproof or indestructible.

Menace
Whenever Despair Scavenger attacks, you may have target creature get -1/-1 until end of turn.

{2}, {T}: Put a +1/+1 counter on target creature you control.
{2}, {T}, Sacrifice Inspiring Effigy: Put a +1/+1 counter on each creature you control.

Glitch {1} (Remove one [restriction] for each time you pay the glitch cost.)
Take an extra turn after this one.
[Skip the untap step of that turn.]
[Skip the draw step of that turn.]
[Skip the combat phase of that turn.]
Exile Cut Causality.