msem-instigator

As The Mistake enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.
Unveil {5} ({5}: Transform this. Unveil 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.

Thriving Bluff enters tapped.
As Thriving Bluff enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Thriving Grove enters tapped.
As Thriving Grove enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Thriving Heath enters tapped.
As Thriving Heath enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Thriving Isle enters tapped.
As Thriving Isle enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Thriving Moor enters tapped.
As Thriving Moor enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Target permanent gains indestructible and hexproof until end of turn. Remove all -1/-1 counters from it.

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.

Trample

You draw a card, lose 2 life, then create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Destroy target creature with power less than or equal to the number of creature cards in your graveyard.

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

When Troubled Heir dies, create a tapped Plains token.

When Troubled Homesteader dies, draw a card.

Exile target creature. Its controller reveals cards from the top of their library until they reveal a creature card. The player puts that card onto the battlefield, then shuffles all other cards revealed this way into their library.

Activated abilities of creatures you control cost up to {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Search your library and/or graveyard for a creature card with mana value X or less and put it onto the battlefield with an additional -1/-1 counter on it. If you search your library this way, shuffle.

Sacrifice a creature: Two-Faced Aristocrat gains indestructible until end of turn.
Attain {4}{B} ({4}{B}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Unbound Spirit can't be blocked.
When you attain Unbound Spirit, tap target creature. That creature doesn't untap during its controller's next untap step.

Target creature gets +1/+0 and gains indestructible until end of turn. Draw a card if you control an Angel, Demon, Faerie or Spirit.

Put two -1/-1 counters on target creature.
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.)

Hexproof
When Uncharted Leviathan enters, target creature can't be blocked this turn.

Creatures your opponents control get -2/-0 until end of turn.
Draw a card.