msem-instigator

{T}: Add {B} or {R}.
{T}, Sacrifice Sigil of Destruction: Add {B}{R}.

Whenever you discard one or more cards, create a Treasure token and draw a card. This ability triggers only once each turn.
Whenever two or more creatures you control attack, you may discard a card. If you do, target creature can't block this turn.

Whenever you attack, each opponent loses 3 life unless they discard a card or sacrifice a nonland permanent. Repeat this process once.
Fleeting {B}{R} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

Improve {1}{B/R} ({1}{B/R}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
At the beginning of each player's combat, you may have that player create two goaded 1/1 red Goblin creature tokens with haste. Exile those tokens at end of combat. (Until your next turn, they attack each combat if able and attack a player other than you if able.)

Whenever Slyten Connoisseur attacks, crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)
Once each turn, when an artifact you control dies, you may pay 1 life. If you do, draw a card.

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.

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.

Spawning Barrens enters tapped unless you have 15 or less life.
{T}: Add {B} or {R}.

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.

Spires of Caulte enters tapped.
{T}: Add {B} or {R}.
{B}{R}: Until end of turn, Spires of Caulte becomes a 3/2 black and red Construct creature with with menace and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

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]: Sun King's Shadow deals 2 damage to target creature or planeswalker and you gain 2 life. If that permanent was already dealt damage this turn, destroy it.

As Sunless Ridge enters, you may tap an untapped creature you control. If you don't, Sunless Ridge enters tapped.
{T}: Add {B} or {R}.

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.

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.)