msem-instigator

{B}, Discard a card: 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.)

Once during each of your turns, you may cast a legendary creature or planeswalker spell from your graveyard.
Sacrifice Pallid Herald: Exile up to three target cards from graveyards.

{W}: Parish Custodian gains lifelink until end of turn. (Damage dealt by this creature also causes you to gain that much life.)

When Profaner of Souls enters, you may return target creature card with mana value 2 or less from your graveyard to the battlefield.
Revive {6}{B} ({6}{B}, 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.)

Whenever Qalami Barbarian attacks, you may discard a card. If you do, it gets +1/+2 and gains menace until end of turn.

Whenever Quick-Witted Slayer deals combat damage to a player, you draw a card and you lose 1 life.

Whenever Ravencaller or another creature enters from your graveyard, create a 1/1 blue Bird creature token with flying.

When Razorshell Marauder enters, you may sacrifice a land or exile a land card from your graveyard. When you do, target creature gets -1/-1 until end of turn and can't block this turn.

Whenever Recurring Abomination deals combat damage to an opponent, you may put target creature card with mana value 3 or less from a graveyard onto the battlefield under your control.
{4}{B}{B}: Return Recurring Abomination from your graveyard to the battlefield tapped.

At the beginning of your upkeep, if a library has twenty or fewer cards left in it, return Returned Explorer from your graveyard to the battlefield tapped.

As long as there are three or more creature cards in your graveyard, Returned Minotaur gets +1/+1 and has menace.

Whenever a Survivor you control dies, target creature you don't control gets -1/-1 until end of turn.

When Saffrisa's Darkcaster enters, look at the top four cards of your library. You may substantiate a card from among them. Put the rest into your graveyard. (To substantiate a card, put it onto the battlefield face down as a 2/2 creature. You may turn it face up and cast it at any time for its mana cost if it isn't a creature.)

{B}, Pay 1 life: Target creature's controller sacrifices it unless that player pays 1 life.
{B}, Sacrifice a creature: You gain life equal to the sacrificed creature's power.

When Scion of Sarrithaz enters, create a 2/2 black Zombie creature token.
{2}{B}, Sacrifice a creature: Draw a card.

When Scorpid Sniper enters, you may have target creature get -1/-1 until end of turn.

Whenever you cast your second spell each turn, each opponent loses 1 life and you gain 1 life.

Deathtouch
{U/B}: Change a target of target spell or ability that targets Serafina to another creature you control.
Whenever Serafina deals damage to a player, at the beginning of the next end step, that player loses life equal to the life they lost this turn.

Menace
When Setar Ritualist enters or whenever you cast a spell, if {U}{R} was spent to cast it, Setar Ritualist deals 3 damage to target permanent, then tap that permanent. Put a +1/+1 counter on Setar Ritualist.

Lifelink
Whenever an Aura becomes attached to Shrieking Gnoll, put a +1/+1 counter on Shrieking Gnoll, then target creature an opponent controls gets -1/-1 until end of turn for each +1/+1 counter on Shrieking Gnoll.

When Silencing Guardian enters, you may have target creature get -1/-1 until end of turn.

Silent Doom enters tapped.
You may cast Silent Doom from your graveyard as long as you sacrificed a permanent this turn.
Cycling {B} ({B}, Discard this card: Draw a card.)

{2}, Pay 2 life: Silkwrap Brawler gains indestructible until end of turn.

When Specimen Collector enters, you may salvage a creature card. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

Flying
Sacrifice a Fungus, Saproling, Plant, or Insect: You gain 2 life.