msem-instigator

{2}{B}, Sacrifice a creature: Draw a card. You gain 1 life.

When Master of the Abyss enters, draw two cards, then discard a card.
{2}{U}{U}, {T}, Discard two cards: Create an X/X black Horror creature token, where X is the number of cards in your graveyard.

When Sandbluff Enforcers enters, detain target creature an opponent controls. (Until your next turn, that creature can't attack or block and its activated abilities can't be activated.)

Deathtouch
Inspired — Whenever Scar Tattooist becomes untapped, you may have target creature get -1/-1 until end of turn.

Sacrifice another creature: Grisly Rougarou deals damage equal to the sacrificed creature's power to any target.

When Hex Maniac enters, return target non-Human creature card from your graveyard to your hand.

Flying, vigilance
Whenever a land you control enters, create a 2/2 green Ox creature token.
{3}{W}, Tap three untapped Oxen you control: Put a +1/+1 counter on each creature you control.

Flying
Whenever Acabo, the Fabled Falcon attacks, you choose how up to one target creature an opponent controls blocks this turn.

When Sigiled Bulwark enters, search your library for a creature card and a noncreature card and reveal them. An opponent chooses one of those cards. Shuffle the chosen card into your library, then put the rest into your hand.

When Suburban Runebrawler enters, exile target instant or sorcery card with mana value 2 or less from your graveyard.
Landfall — Once each turn, when a land you control enters, you may cast a copy of the exiled card without paying its mana cost.

When Breaker of Secrets enters, each player mills three cards from each of their libraries.
Recite {U} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Crazed Bruiser attacks, it gets +2/+0 until end of turn.

Each opponent loses 2 life and you gain 2 life. You mill two cards.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

{U}, Sacrifice a creature: Discard a card, then draw a card.

{T}, Pay 1 life: Add {W} or {U}.
{2}, {T}, Sacrifice Haunted Manor and another permanent: Draw a card. Activate only during your turn.

Put a +1/+1 counter on up to one target creature. Untap it. You gain 3 life.

Desolate Path enters tapped unless you control one or fewer other lands.
{T}: Add {W} or {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

When Volaris Tideshaper enters, look at the top four cards of your library. Put one of those cards into your hand. and the rest on the bottom of your library in a random order.
Whenever you cast a noncreature spell, Volaris Tideshaper can't be blocked this turn.

When Old-Oath Conviction enters or leaves the battlefield, create a 1/1 white Cleric creature token with lifelink.
{3}{B}, Sacrifice Old-Oath Conviction: Draw a card. Activate only as a sorcery.

As long as it's your turn, Vanguard of Glory has first strike.

Double strike
Whenever an Equipment you control enters, create a 3/3 white Archon creature token with flying and attach that Equipment to that token.

When Beyond the Boneyard enters, exile another target nonland permanent until Beyond the Boneyard leaves the battlefield.
Your opponents can't cast spells that share a card type with the exiled card during postcombat main phases.

Improve {G} ({G}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever an Elf you control dies, you may search your library for a land card, reveal it, put it into your hand, then shuffle.

Prowess
Grizzled Stoker can't be blocked as long as you control an artifact.

Defender
Whenever you cast an enchantment, instant, or sorcery spell, scry 1 if it's the first time this ability has resolved this turn. If it's the second time, Prismscale Piranhas can attack this turn as though it didn't have defender. If it's the third time, whenever Prismscale Piranhas deals combat damage to a player this turn, draw a card.