msem-instigator

When Sable Evangelist enters, create a 0/1 black Cultist creature token with “{1}{B}{B}, Sacrifice three Cultists: Create a 5/5 black Demon creature token.”
Cultists you control get +2/+0 and can't block.

Salome's Messenger enters tapped.
Whenever you cast your second spell each turn, you may return Salome's Messenger from your graveyard to your hand.

Sanguine Oracle enters tapped.
{4}{B}, {T}, Sacrifice Sanguine Oracle: Target player discards two cards. Activate only as a sorcery.

Poisonous 2 (Whenever this creature deals combat damage to a player, that player gets two poison counters.)
When Sankataar Scourge dies, if it attacked this turn, target opponent gets a poison counter.

When Scaleblight Warrior enters, you gain 2 life.
Pay 2 life: Scaleblight Warrior gains menace until end of turn.

At the beginning of your end step, each opponent loses 1 life for each permanent they own that you control.

{3}{B}, Exile Screeching Duneborn from your graveyard: You gain 1 life and draw a card.

At the beginning of your draw step, draw an additional card and you lose 1 life. Then if you have six or fewer cards in hand, sacrifice a creature.

At the beginning of your upkeep, you may pay {B}. If you do, return a Wizard card from your graveyard to your hand.

Shadowband Consul enters tapped.
{B}, Pay 2 life: Return Shadowband Consul from your graveyard to the battlefield. Activate only if an opponent lost life this turn.

Menace
Art of war — At the beginning of your end step, if Shikai Hunters dealt damage to an opponent this turn, put a +1/+1 counter on it.

Shikai Revenant enters tapped.
At the beginning of your end step, if an opponent lost life this turn, you may return Shikai Revenant from your graveyard to your hand.

Flying
Sacrifice a creature: Shrieking Nightwing gets +1/+1 until end of turn.

Whenever a storied permanent you control enters, each opponent loses 1 life and you gain 1 life. (Enchantments and legendary permanents are storied.)
{2}{B}{B}, Sacrifice Sinister Heir: Return target storied card from your graveyard to the battlefield.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
{2}{B}, Sacrifice Sluiceway Shrieker: Put the bottom card of your library into your hand.

Whenever you cast a noncreature spell, you may pay {U}. If you do or the spell was cast from your graveyard, draw a card.

Whenever Stargaze Spirit or another creature dies, you may gain 1 life.
Revive {3}{W} ({3}{W}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Trial 3 (As you cast this spell, an opponent of your choice may pay 3 life. If they don't, they fail the trial.)
When Steeple Deadeye enters, if the trial was failed, you gain 3 life and put a +1/+1 counter on Steeple Deadeye.

When Sunset Cliffs Patron enters, you may post a bounty on target creature. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)

Syndicate Sycophant can't block.
When a creature scavenges Syndicate Sycophant, you may search your library for a card named Syndicate Sycophant, reveal it, put it into your hand, then shuffle.
Scavenge {2}{B} ({2}{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.)

Whenever The Ever-Pestilent deals combat damage to a player, that player discards a card at random.

{1}{B}: Target Knight or Soldier you control gains deathtouch until end of turn.

When Thoughtslick Engineer enters, each player discards a card at random.

Embellish {3}{B} (If you cast this spell for {3}{B}, create a 1/1 blue Thopter artifact creature token with flying when it enters.)
Tidehollow Lich can't block.
You may cast Tidehollow Lich from your graveyard as long as you control an artifact creature.

Flying
Tizerus Bats can't block unless you control another creature with flying.