msem-instigator

Flying
When Sweeper Drone enters, create a Function token with “Put a +1/+1 counter on each creature named Sweeper Drone you control.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Reach
Whenever another creature enters, untap Sylvan Subversive.

Menace, prowess

{T}, Sacrifice Synthetic Seedling: Choose a basic land type. Create a tapped colorless enchantment land token with the chosen type.

Target creature gets +1/+2 and gains flying until end of turn.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

When Tamer of the Ton dies, create a 4/4 green Chimera creature token.

Deathtouch
Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
Whenever an opponent has less life or fewer cards in their main library than the number of Curses attached to them, they lose the game.

Enchant opponent
Whenever enchanted player is attacked, you may discard a card. If you do, draw a card.

Enchantment creatures you control get +2/+2.

Search your library for a card, put that card into your hand, then shuffle. If you control two or more creatures with -1/-1 counters on them, add {B}{B}{B}.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

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

Create an X/X green Mutant creature token.
Draw a card.

Flying, haste
Whenever The Branded Usurper attacks, it deals 2 damage to any target.
If you would lose the game, instead exile The Branded Usurper. Your life total becomes 0. Until an opponent's next turn, you can't lose the game and you can't gain life. Take an extra turn after this one.

Flying
Whenever a creature attacks you or a planeswalker you control, put a -1/-1 counter on that creature.

At the beginning of your upkeep, destroy target creature with the greatest power or tied for greatest power among creatures on the battlefield. Then if there are no creatures on the battlefield, sacrifice The Empty Throne.

Flying
Creatures you control have “{T}: Add {C} or one mana of any color.”
{X}: The Finest Specimen gets +X/+X until end of turn.

Cards in your hand have lifecycle {3}.
{2}{G}, Sacrifice four creatures: Create two tapped 4/4 green Chimera creature tokens.
Lifecycle {3} ({3}, Discard this card: Create two tapped 1/1 colorless Elemental creature tokens.)

Haste
Whenever The Marquess Devonport attacks, it deals 2 damage to you.
Attain {5}{R} ({5}{R}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

When The Struggle for Death enters, choose target creature you don't control. Any number of creatures you control fight that creature.
Whenever a creature dies, look at the top card of your library. You may put it into your graveyard.

Draw three cards. Then discard two cards unless you discard an instant or sorcery card.

When Thought Paradigm enters, conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)
Whenever you cast a sorcery spell, target player mills three cards.

Flash
When Threadripper Savant enters, put a stun counter on up to one target creature.

Menace
Titan of Fallen Stars gets +1/+1 from -1/-1 counters instead of -1/-1.
When Titan of Fallen Stars enters, move any number of -1/-1 counters from creatures you control onto Titan of Fallen Stars.

As an additional cost to cast this spell, you may discard a card. If you do, this spell costs {4} less to cast.
Total Process Failure deals 5 damage to target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.

When Trainer of the Abyss dies, create a 1/1 black Demon Hound creature token with deathtouch.