msem-instigator

Haste
When Magmatic Violator enters, target opponent sacrifices a creature.
At the beginning of the end step, sacrifice Magmatic Violator.

Trample
Other Beasts you control have trample.
Whenever Magnoceros attacks, create a 5/5 green Beast creature token that's tapped and attacking.

Enchant creature
When Make Way enters, draw a card.
Enchanted creature can't block.

{T}: Add one mana of any color.

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Spend this mana only to cast a legendary spell or activate an ability of a legendary permanent.
{3}, {T}, Sacrifice Many-Voiced Tower: Search your library for a legendary card, reveal it, put it into your hand, then shuffle. Activate only if you control five or more differently named lands.

When Marauding Goliath becomes blocked by a creature with power 1 or less, sacrifice it at end of combat.

Civilized — When Marble Row Healer enters, if you control an artifact, a creature, and an enchantment, you gain 4 life.

Menace (This creature can't be blocked except by two or more creatures.)
Whenever a nontoken creature you control dies, exile the top card of your library. You may play that card until the beginning of your next end step.

When Master of Marble Row enters, choose one —
• Create a colorless Monument artifact token with “Creatures you control get +1/+1.”
• Create a white Cloister enchantment token with “When this enchantment enters, exile target nonland permanent an opponent controls until this enchantment leaves the battlefield.”

I, II — Put a +1/+1 counter on target creature you control.
Discovery — Creatures you control with +1/+1 counters on them have lifelink.

Whenever Merchant of Flesh or another creature you control dies, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
{B}, Sacrifice two Treasures: Each opponent sacrifices a creature.

This spell can't be countered.
Whenever Meren, Bane of the Cairns attacks, exile target creature card from your graveyard. You may cast that card for as long as it remains exiled by sacrificing a creature in addition to paying its other costs.

I, II — Target creature you control gets +2/+0 and gains menace until end of turn.
Discovery — Attacking creatures you control get +2/+0 and have menace.

Embellish {4}{W} (If you cast this spell for {4}{W}, create a 1/1 blue Thopter artifact creature token with flying when it enters.)
When Meticulous Mechanist enters, scry 1.

Hexproof
Mist-Valley Ancient enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

{1}{R}, Discard a card: Draw a card. Mist-Valley Minotaurs gets +2/+0 until end of turn.

Assault {2}{R} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Monstrous Hila assaults, it deals 3 damage to any target.

Exile target creature or planeswalker, then exile its controller's graveyard.

Whenever a nontoken creature you control enters, if it shares no creature types with other creatures you control, draw a card.

{T}: Add {C}.
Whenever Mustering Grounds becomes tapped, if it's enchanted, you may pay {2}. If you do, create a 1/1 white Soldier creature token with vigilance.

I, II — Look at the top four cards of your library. You may reveal a permanent card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Discovery — At the beginning of your end step, you may put a permanent card from your hand onto the battlefield.

Stampede — Whenever Nacatl Skirmisher and a creature with greater power attack, creatures you control get +1/+0 until end of turn.
{R}, Sacrifice Nacatl Skirmisher: Destroy target artifact.

When Naga Cultivator enters, you may put a land card from your hand onto the battlefield.

Nameless Throng can't block.
{1}{B}, Exile an artifact or enchantment card from your graveyard: Return Nameless Throng from your graveyard to the battlefield.