msem-instigator

[+2]: Discard a card at random. If you do, draw two cards.
[0]: Target creature's controller may pay X life. If they don't, you lose X life and gain control of it (Choose any number for X.)
[–3]: Flip a coin until you lose a flip or choose to stop flipping. For each flip you won, draw two cards and create a tapped Treasure token.

Flash
Enchant creature
Enchanted creature gets -3/-0 and doesn't untap during its controller's untap step.

Foretell {B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Destroy target creature or planeswalker. You lose 4 life unless this spell was foretold.

When Palesoul Mender dies, you gain life equal to its toughness.

Whenever Grin, Scourge of Goresand attacks, when you next cast an instant or sorcery spell with mana value 3 or less this turn, copy that spell. You may choose new targets for the copy.
Dash {2}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

When Naive Apprentice enters, each player creates a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
As long as an opponent controls an artifact, Naive Apprentice gets +2/+0.

Primal {R} (During your turn, you may cast this spell for {R} instead of playing a land.)
Target creature gets +4/+0 and gains trample until end of turn.

Rhapsody {4}{R}{R} (Pay {4}{R}{R} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Menace

Exile target creature you control, then return that card to the battlefield under your control. Scry 1.

Deathtouch
{T}, Sacrifice another creature: Add two mana of any one color.

Primal {1}{W}{W} (During your turn, you may cast this spell for {1}{W}{W} instead of playing a land.)
Double strike
When Sunken Slasher enters, if you didn't play a land this turn, put a +1/+1 counter on it.

Search your library for a Spirit card, exile it, then shuffle. You may cast that card this turn.

Purger of Blights enters with a -1/-1 counter on it.
{2}{B}{G}, {T}, Remove a -1/-1 counter from a creature you control: Draw a card.

Return up to two target instant and/or sorcery cards from your graveyard to your hand, then you may cast an instant or sorcery card with mana value 2 or less from your hand without paying its mana cost. Exile Alchemical Warfare.

Flamingo Rock enters tapped unless you played it from exile.
{T}: Add {U} or {R}.

Koth's Retaliation deals 4 damage to target creature. When that creature dies this turn, exile its controller's graveyard.

Gain control of target artifact or creature until end of turn. Untap it. If it's a creature, it gains haste until end of turn and up to one target creature can't block it this turn.

Destroy target land. Sandburst deals 1 damage to each creature without flying your opponents control.

You may look at the top card of your library any time.
Once during each of your turns, you may cast an enchantment spell from the top of your library or from your graveyard.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{2}{R}{R}: If an instant or sorcery source you control would deal damage to a permanent or player this turn, it deals that much damage plus 2 instead.

Renown 1
Whenever a creature you control becomes renowned, exile the top card of your library. You may play that card this turn.

When Gau Ding Soulhoard dies, create X 1/1 colorless Spirit creature tokens, where X is its power.
Scavenge {4}{B} ({4}{B}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Enchant player
When Curse of the Hunter's Moon enters, create a 2/2 green Wolf creature token.
Whenever enchanted player is attacked, the attacking player adds {R}. Until end of turn, that player doesn't lose that mana as steps and phases end.

Creatures you control get +1/+1 and gain trample until end of turn.
Reconstruct {4}{G} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)

Flying
Whenever Starborne Hellkite attacks, choose two—
• Starborne Hellkite deals 4 damage to any target.
• Destroy target artifact or land.
• Creatures you control get +2/+0 until end of turn.