msem-instigator

When Abyssal Nightcaster enters, each player exiles a card from their hand.
When Abyssal Nightcaster dies, you may play cards you don't own from exile this turn.

When Acolyte of Night dies, each opponent loses 1 life.

At the beginning of your upkeep, if you control four or more Swamps, you may exile target creature card from your graveyard. If you do, create a tapped token that's a copy of it except it's a black Mummy.

Deathtouch
When Aldrane's Masterpiece enters, look at the top six cards of your library. You may put a Zombie card with lesser mana value from among them onto the battlefield. Put the rest on the bottom of your library in a random order.
Other Zombies you control get +1/+1.

When Alenian Cruel-Star enters, put a +1/+1 counter on it if you control another Goblin.

Sabotage — Whenever an opponent or permanent an opponent controls becomes the target of a spell you control, return target creature card with mana value 3 or less from your graveyard to the battlefield.

{B}: Remove a counter from target permanent.
{3}{B}: Move a counter from target permanent onto Ashfeaster Ghouls. Ashfeaster Ghouls can't be blocked this turn.

Deathtouch
When Backstage Comic enters, target player discards a card.

Lifelink
Whenever Backstage Prompter deals combat damage to a player, put a +1/+1 counter on it.

Flying, deathtouch

Deathtouch, lifelink
Whenever Batwing Initiate deals combat damage to a player, put a +1/+1 counter on it.
Pay 4 life: Batwing Initiate gains flying until end of turn.

Bearer of Fables gets +1/+1 for each enchantment you control.
{2}{G}: Look at the top four cards of your library. You may reveal an enchantment card or a card with fabled from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Whenever another creature you control dies, put a +1/+1 counter on Belligerent Mob.

{T}, Exert Bestower of Princely Sin: You may sacrifice another creature. If you do, target opponent may sacrifice a permanent that shares a card type with it. If they don't, that player loses 1 life and you draw a card. Repeat this process for artifact, enchantment, land, and planeswalker. Activate only as a sorcery.

When Bezoarbeast dies, each opponent loses 2 life and you create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

When Black Cat dies, target opponent discards a card at random.

Deathtouch
{B}, Pay 1 life: Add one mana of any color. Activate this ability only once each turn.

Whenever Blackfeather Cleric enters or attacks, exile target card from a graveyard. Put a +1/+1 counter on Blackfeather Cleric if it was a permanent card. Otherwise, you gain 1 life.
Surpass {5}{B} ({5}{B}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

When Blade of Reolem dies, target opponent discards a card at random.

Poisonous 1 (Whenever this creature deals combat damage to a player, that player gets a poison counter.)
Blade of the Serpent gets +1/+1 as long as an opponent is poisoned.

Whenever another creature you control dies, you may pay {1}. If you do, scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

{1}{B}: Regenerate Brainless Ghoul. (The next time this creature would be destroyed this turn, it isn't. Instead tap it, remove all damage from it, and remove it from combat.)

When Burglar Cat enters, exile the top card of target opponent's library. You may play that card during any turn you attacked with a Rogue, and you may spend mana as though it were mana of any color to cast it.

Flying
Whenever Carrier Pigeon attacks or blocks, target creature gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)

Flying
When a creature you control scavenges Carrion Courier, put a flying counter on that creature.
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.)