msem-instigator

Foretell {B}{R} (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.)
Haste
Whenever Sofia deals combat damage to an opponent, exile the top card of that player's library face down and look at it. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any type to cast that spell. Then foretell Sofia. It costs {0} to foretell this way.

Menace
Whenever a nontoken Warrior you control dies, create a token that's a copy of it, except it's 1/1.

Gain control of target creature until end of turn. Untap that creature. It gains lifelink and haste until end of turn.

Source Decay deals 2 damage to each opponent. Create two 1/1 colorless Servo artifact creature tokens.
Whenever a creature you control deals combat damage to a player, you may pay {2}{B}{R} and sacrifice it. If you do, return Source Decay from your graveyard to your hand.

Speckled Outcast has menace as long as it's enchanted.

Gain control of target creature until end of turn. Untap it. Until end of turn, it gets -1/-1 and gains haste.

Flash
If an opponent would gain life or damage to a permanent or opponent would be prevented, instead Spirit-Lantern Incendiary deals 1 damage to that permanent or opponent.

Whenever Starfall Instructor attacks, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Each opponent loses 2 life.

Target opponent discards a card at random. If that card's mana value is 3 or less, you may cast it without paying its mana cost.

Wither (This deals damage to creatures in the form of -1/-1 counters.)

Menace
At the beginning of your end step, if you lost 4 or more life this turn, you may create Irgh'vall, a legendary 4/4 black Demon creature token with flying.

As an additional cost to cast this spell, discard a card.
Draw two cards unless any opponent discards two cards.

[+1]: Each opponent loses 1 life for each card you've drawn this turn. Then you draw a card.
[–2]: Shi Hou, the Sun King deals 2 damage to target creature or planeswalker and you gain 2 life. If that permanent was already dealt damage this turn, destroy it.

Target creature deals damage equal to its power to its controller.

First strike
Whenever Ren deals combat damage to a player, you may activate one of her abilities by paying 3 life rather than paying its cost.
{1}{R}, Discard a card: Draw a card.
{2}{B}, Sacrifice a creature: Each opponent sacrifices a creature.

[+1]: The next card you foretell this turn costs {0} to foretell. You may discard a card. If you do, draw a card.
[–3]: Teufel deals 4 damage to any target and you gain 4 life.
[–6]: You get an emblem with “Whenever you cast a spell, you may pay life equal to the amount of mana spent to cast it. If you do, copy that spell and you may choose new targets for the copy.”

First strike
Whenever The Heart-hardened or another creature you control dies, each opponent loses 1 life. If this is the third time this ability has resolved this turn, you draw three cards and you lose 3 life.

When The Marrow Lord enters, search your library for a card with arise, put that card into your graveyard, then shuffle.
Whenever you activate an ability of a card in your graveyard or a creature you control enters from a graveyard, this creature deals 1 damage to any target.

Each player sacrifices three lands. Torment each player three times. (To torment a player, they lose 3 life unless they discard a card or sacrifice a nonland permanent.)

Glorious end — When Toros the Warchief dies, if it was tapped, return it to the battlefield at the beginning of the next end step.
Attacking creatures you control have deathtouch.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever a marked creature dies, target player discards a card.

When Traversing the Hellwastes enters, create a 1/1 green Scout creature token. It gains haste until end of turn.
Whenever a creature you control enters, you may pay 2 life. If you do, draw a card.

Target player sacrifices a creature.
Inscribe {3}{B}{R} ({3}{B}{R}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Flying, haste
Whenever another creature dies, Twinfire Dragon gets +1/+0 until end of turn.

When you cast this spell, copy it for each Dragon permanent you control. You may choose new targets for the copies.
Tyrant's Breath deals 7 damage to target creature or planeswalker.