msem-instigator

Whenever an artifact you control enters or is put into a graveyard from the battlefield, Workshop Engineer gets +1/+1 until end of turn.

Menace
Whenever you cycle A Most Important Prince or it attacks, each opponent with two or more cards in hand discards a card.
Basic landcycling {1}{B} ({1}{B}, Discard this card: Search your library for a basic land card, reveal it, and put it into your hand, then shuffle.)

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
{4}{B}{B}, {T}, Sacrifice Abalone Abomination: Create an X/X black Horror creature token, where X is the number of cards in your graveyard.

Engorge (As this enters, mill three cards, then exile a card from among the milled cards.)
When Abhorrent Exhumer enters, if it engorged a creature card, you may return target creature card from your graveyard to your hand.

Menace
Whenever a creature an opponent controls dies, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Menace
At the beginning of your upkeep, put a prize counter on target permanent you don't control.
Whenever a permanent with a prize counter on it is put into a graveyard from the battlefield, return it to the battlefield under your control.

When Arisen Haploc enters, return target creature card from a graveyard to its owner's hand.
Revive {5}{B}{B} ({5}{B}{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.)

When Astrid, Disgruntled Princess enters, destroy target creature with mana value less than or equal to the number of Warriors you control.

Desecrate (When this creature enters, you may sacrifice an artifact or land.)
When Back-Alley Vandal desecrates a permanent, put a +1/+1 counter on Back-Alley Vandal.

When Battery Courier dies, lose 2 life.

Whenever you cast an enchantment spell, you draw a card and you lose 1 life.
Whenever one or more counters are put on an enchantment you control, you gain 1 life and each opponent loses 1 life.

At the beginning of combat on each of your turns, look at the top card of your library. You may put that card into your graveyard.
Whenever a land card is put into your graveyard from anywhere, each opponent loses 1 life and you gain 1 life.

{1}{B}, {T}: Target creature gets +2/+2 and gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)
{3}{B}{B}, {T}: Target creature gets -2/-2 and gains winnow until end of turn.

Cycling {2} ({2}, Discard this card: Draw a card.)
{3}{B}{B}, Exile Bloated Visceroid from your graveyard: Create two 2/2 black Zombie creature tokens. Activate only as a sorcery.

When Catacomb Dredger dies, return another target creature card from your graveyard to your hand.

Flash
When Charnel Legion enters, destroy target creature or planeswalker an opponent controls that was dealt damage this turn. When you do, you gain 2 life.

Whenever another creature you control dies, target player loses 1 life and you gain 1 life.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever a marked creature dies, you lose 1 life and you draw a card.

Adorned — Coven Adherent has indestructible as long as it's equipped and/or enchanted.

Whenever Culling Claw attacks, target creature gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)

Menace
Whenever CySec Blacksuit deals combat damage to a player or planeswalker, create a Function token with “Choose a nonland card exiled by this spell. For as long as that card is exiled, you may cast it and you mana of any type can be spent to cast that spell.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Augmented — When Dead End Adventurer enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, destroy target creature you don't control.

{B}, Sacrifice another creature: Deranged Apothecary gains indestructible until end of turn.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
{2}, Sacrifice a creature: Put a +1/+1 counter on Desert Marauder.