msem-instigator

Trample
Colossal Greatwurm enters with five +1/+1 counters on it.
Whenever a player draws a card, put a +1/+1 counter on Colossal Greatwurm.
Remove three +1/+1 counters from Colossal Greatwurm: Create a 3/3 green Wurm creature token.

Whenever one or more cards are put into your graveyard from your library, exile one of those cards.
Whenever Colossal Hermit deals combat damage to a player, you may cast a card exiled with it without paying its mana cost.

Equipped creature gets +3/+3.
Equip {4}
Equip creature with power 5 or greater {1}

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)
When Colpah Mystic enters, you may discard a card. If you do, creatures you control named Colpah Mystic get +2/+2 until end of turn.

Whenever Combat Technician attacks, create a 1/1 colorless Servo artifact creature token that's tapped and attacking. Then Combat Technician gets +1/+1 until end of turn for each artifact you control.

Lifelink
Partner with Imperator Valtasius (When this creature enters, target player may put Imperator Valtasius into their hand from their library, then shuffle.)
At the beginning of your upkeep, return target Soldier card from your graveyard to your hand.

When Commander of the Cavalry enters, you may search your library for a creature card with ride, reveal it, and put it into your hand. If you do, shuffle.
{X}, {T}: Put a creature card with ride and mana value X or less from your hand onto the battlefield transformed and attached to another target creature you control without a Steed attached to it.

Creature tokens you control get +1/+1.
{3}{W}: Create a 1/1 white Warrior creature token.

{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.

{T}: Add {C}.
{T}: Untap target legendary creature you control. Activate only once each turn.

Gain control of target creature until end of turn. Untap it. It gains haste until end of turn.
Rerun (If you cast this from your hand, exile it as it resolves. Whenever a creature you control dies, you may cast this card from exile without paying its mana cost.)

Whenever a player casts a spell, each opponent mills a card.

If a player would draw one or more cards except for the first one they draw in each of their draw steps, they exile a card from their hand before they draw those cards.
{1}, {T}: Until end of turn, you may play target card exiled with Compromised Vault, and you may spend mana as though it was mana of any color to cast that spell.

When Compulsion's Voice enters, gain control of target permanent until end of turn. Untap that permanent. It gains haste until end of turn.
Recite {1}{U}{R} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

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.

Equipped creature gets +1/+0, has no name, and loses all non-Pirate, non-Rogue creature types.
{1}: Equipped creature gains the creature types and activated abilities of target creature and its name becomes that creature's name until end of turn.
Equip {1}

Shuffle your hand into your library, then draw X cards.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Whenever Conchhorn Shinygrabber attacks, you may pay {1}. If you do, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
{W}{U}{B}{R}{G}: Conchhorn Shinygrabber gets +3/+3 and gains lifelink until end of turn.

Destroy target creature. (Cast a copy of this spell once while this creature is on the battlefield.)

Each player draws a card, then target player mills X cards, where X is the number of cards players have drawn this turn.

Whenever you cast an enchantment spell, create a 1/1 white and black Bird creature token with flying and vigilance.
Whenever three or more creatures you control deal combat damage to a player, that player sacrifices a creature. If they can't, they discard a card.

When Confining Priest enters, exile another target creature with power 4 or less an opponent controls until Confining Priest leaves the battlefield. (That creature returns under its owner's control.)

An opponent separates all noncreature, nonland cards in your graveyard into two piles. Put one pile into your hand and exile the other. Exile Conflicting Records.

When Conflux Ravager enters, destroy target nonland permanent an opponent controls.
Cycling {2} ({2}, Discard this card: Draw a card.)

As a spell you control is countered by a spell or ability an opponent controls while you control a Mountain, you may reveal Confront the Riddlemaster from your hand. When you do, cast it without paying its mana cost.
This spell can't be countered.
Confront the Riddlemaster deals 4 damage to any target.