msem-instigator

Flying, haste
Whenever Rhyolithic Hellkite attacks, you may sacrifice a land or exile a land card from your graveyard. If you do, put a +1/+1 counter on Rhyolithic Hellkite.

Choose one —
• Destroy target monocolored creature.
• Ria-Demian Charm deals 2 damage to each creature.
• Each player discards two cards and loses 2 life.

{T}: Add {C}.
{T}, Pay 1 life: Add {B} or {R}.

({T}: Add {B} or {R}.)
Ruined Shrine enters tapped unless you control two or more basic lands.

({T}: Add {B} or {R}.)
As Ruptured Flats enters, you may pay {1}. If you don't, Ruptured Flats enters tapped.

Destroy target creature. Creatures without flying can't block this turn.

Flash
First strike (This creature deals combat damage before creatures without first strike.)

Sammel Wyldjack enters with a fuse counter on him.
At the beginning of your upkeep, remove a fuse counter from Sammel Wyldjack. If you do, each player sacrifices four lands and Sammel Wyldjack deals 4 damage to each other creature.

Menace
Cycling {R} ({R}, Discard this card: Draw a card.)

Flying
Improve—{1}{B/R}, Sacrifice a creature. ({1}{B/R}, Sacrifice a creature: 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.)
Whenever another creature you control dies, each opponent loses 1 life and you gain 1 life. If that creature was sacrificed, instead each opponent loses 2 life and you gain 2 life.

Whenever Scathing Critics deals combat damage to a player or planeswalker, put a +1/+1 counter on it.

Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Whenever you put one or more -1/-1 counters on Scion of Fiends or another creature, Scion of Fiends deals that much damage to each opponent.

Enchant creature
Enchanted creature gets +2/-2.

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever a creature with wither deals combat damage to an opponent, Scorchmark Seer deals 2 damage to that player.

Until end of turn, target creature gains “When this creature is dealt damage, destroy it.” (Then exile this card. You may cast the creature later from exile.)

This spell costs {2} less to cast for each creature that died this turn.
Each player exiles all creature cards from their graveyard, then sacrifices each creature they control, then puts all creature cards they own exiled this way onto the battlefield. Exile Sea of Corpses.

Another target player reveals their hand. You may choose a nonland card from it. That player discards that card.
Fuse (You may cast one or both halves of this card from your hand.)

Another target player reveals their hand. You may choose an instant or sorcery card from it and cast it without paying its mana cost.
Fuse (You may cast one or both halves of this card from your hand.)

At the beginning of your end step, for each opponent, destroy up to one target creature that player controls with power less than or equal to the amount of life that player lost this turn.
{3}{R}: Selezzar, Tyrant of Endak deals 2 damage to each opponent.

When Shala Na enters, each player chooses a creature they control, then sacrifices the rest.
[+1]: Up to one target creature you control gains double strike and haste until end of turn.
[–6]: You get an emblem with “Whenever a creature dies, each opponent loses 2 life.”

Haste
Whenever Shala's Phantasm attacks, you may sacrifice a creature. If you do, Shala's Phantasm deals 3 damage to any target.

When Shaman of Burning Ashes enters, return target instant or sorcery card from your graveyard to your hand. When you do, each opponent loses X life, where X is that card's mana value.

Choose two —
• Target creature gets +2/+0 until end of turn.
• Two target creatures can't block this turn.
• Target player discards two cards, then draws a card for each card they discarded this way.
• Shi Hou's Command deals 4 damage to target legendary creature or planeswalker.

(Transcend as a sorcery to gain that type and a +1/+1 counter.)
Ward—Discard a card.
{B}{R}: Demigod — Draw a card, then discard a card. You may have each opponent sacrifice a nonland permanent with the same mana value as the discarded card.
{4}{B}{R}: God — Create two tokens that are copies of Shi Hou's back face.

Shoupan Shrine enters tapped.
{T}: Add {B} or {R}.
{B/R}, {T}, Sacrifice Shoupan Shrine: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.