msem-instigator

Whenever you cast a black spell, choose up to X, where X is the number of black mana symbols in that spell's mana cost —
• Target player loses 1 life and you gain 1 life.
• Put a -1/-1 counter on target creature.
• You draw a card and you lose 3 life.
• Exile target card in a graveyard.

Lifelink
At the beginning of your upkeep, Osgaerith Desecrator deals 1 damage to up to one target creature.

When Osseous Augur enters, target creature an opponent controls gets -1/-1 until end of turn. If that creature's controller is cursed, that creature gets -3/-3 until end of turn instead.

At the beginning of your upkeep, each player discards a card. Then if a player has no cards in hand, you may transform Performer of Ambition.

When Piruz, the Fourth Shah enters, discard your hand. For each creature card discarded this way, create a 3/3 black Demon creature token with flying. For each other card discarded this way, you gain 3 life.
Monument {5}{B}{B} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

Preacher of the Yenzu gets +2/+0 and has flying as long as you control a legendary creature.

Deathtouch
Foresight — Whenever you draw your second card each turn, each opponent loses 1 life and you gain 1 life.
{1}{B}: Qalam Surveyor gains menace until end of turn.

Lifelink
When Ravenous Tarwurm enters, you may have it consume. When you do, it deals 3 damage to target creature. (To consume, sacrifice another creature or exile a creature card from your graveyard.)

Whenever you sacrifice a permanent, put a +1/+1 counter on Restless Oppressor.

When Scion of Pestilence enters, create a black enchantment token named Blight with “At the beginning of your upkeep, you lose 1 life.”

When Scrapyard Aberration enters, you may sacrifice another artifact. If you do, target creature gets -2/-2 until end of turn.

Defender (This creature can't attack.)
Adorned — Secluded Wildborn can attack as though it didn't have defender as long as it's equipped and/or enchanted.

Sabotage — Whenever an opponent or permanent an opponent controls becomes the target of a spell you control, target creature you control can't be blocked this turn.
{B}{B}{B}: Secret Thief gets +3/+0 until end of turn.

Whenever a Survivor you control dies, you draw a card and you lose 1 life.

Death knell — Put a +1/+1, flying, lifelink, or menace counter on Senn, the Haunting Gaze, then trigger a death knell of another permanent you control. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

When Shark Slayer enters, you may destroy target creature with mana value less than or equal to the number of artifacts you control.

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Slums Thug gets +1/+1 and has menace as long as you've gained life this turn.

Flying, deathtouch
Creatures that aren't Spirits or Warlocks get -1/-1.

Flying, lifelink
Skip your draw step.
Pay 3 life: Draw three cards. Activate only as a sorcery and only once each turn.

Lifelink
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Spoiled Oracle mentors a creature, that creature gains lifelink until end of turn.

Flying
{B}, Sacrifice another creature: Draw a card.

Flying
Whenever a creature dealt damage by Subturgian Legionnaire this turn dies, create a 1/1 black Vampire creature token with lifelink.

Primal {1}{G}{G} (During your turn, you may cast this spell for {1}{G}{G} instead of playing a land.)
When Swampedge Sentinel dies, return another creature card from your graveyard to your hand.

Flying
Other Vampire creatures you control get +1/+0 and have menace.

Advance {3}{B}{B} (Cast this for {3}{B}{B} to advance it as it enters. {3}{B}{B}: Advance this as a sorcery.)
Whenever Tireless Archivist advances, search your library for a card, put it into your hand, then shuffle.