msem-instigator

Flying
When Sky-Torrent Navigator enters, forebode. If you control two or more Pirates, forebode again. (To forebode, create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Flying
When Slighted Spirit enters, detain up to two target creatures. (Until your next turn, those permanents can't attack or block and their activated abilities can't be activated.)

Flying, prowess
When Sphinx Mentor enters or dies, draw a card.

Whenever you cast a spell from your graveyard, you may return target nonland permanent to its owner's hand.
Sacrifice a Clue: Return Trespasser of the Gallows from your graveyard to your hand.

Hexproof

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
Zoulev Envoy can't be blocked.

Bloodline Zealot gets +2/+0 and has menace as long as you've sacrificed a permanent this turn.

Spells you cast from exile cost {1} less to cast.

This spell costs {2} less to cast if an opponent was dealt combat damage this turn.
When Dastardly Duo enters, audition for black. (Create a 1/1 Construct Actor creature token, a Cleric Role giving 2/2 and lifelink, or a Warlock Role giving 2/1 and flying. Roles replace older ones.)

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever a creature an opponent controls dies, its controller discards a card and loses 1 life.
{1}{B}{B}, {T}, Sacrifice another creature: Destroy target creature.

{T}, Sacrifice a creature or land: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.

Landfall — Whenever a land you control enters, target player loses 1 life and you gain 1 life.

Menace
Whenever Hui Zhou, the Dark Visage perseveres, you may destroy another target legendary creature. (A creature perseveres when it survives damage.)

Menace
When Kai'Zhou enters, you may have all legendary nonland permanents phase out until your next turn.
Whenever Kai'Zhou deals combat damage to a player, they sacrifice a legendary permanent.

Whenever another creature you control dies, each other player sacrifices a creature.

Whenever Malignant Afflicted perseveres, destroy target creature an opponent controls that dealt damage this turn. (A creature perseveres when it survives damage.)

{2}: Exile up to two target cards in a single graveyard. If two creature cards were exiled this way, create a 1/1 blue Elemental creature token with flying.

Merciless Champion can't block unless you control another Knight or Soldier.

When P-3 Ambusher enters, you may sacrifice a creature or discard a creature card. If you do, draw a card.

Lifelink
When Pact Equivocator enters, you lose 2 life and draw a card.

Vanishing 5 (This creature enters with five time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever you remove a time counter from Rallios, create a tapped 2/2 black Zombie creature token.

Scion of Belmord has lifelink as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

This spell costs {1} less to cast for each poison counter your opponents have.
Poisonous 1 (Whenever this creature deals combat damage to a player, that player gets a poison counter. A player with ten or more poison counters loses the game.)
At the beginning of your end step, each opponent with seven or more poison counters loses the game.

Menace
Whenever you cast a cryptic spell, you may return target creature card from your graveyard to your hand. (Artifacts, enchantments and modal spells are cryptic.)

Harmony — Warriors you control get +1/+0 and gain menace until end of turn.
Whenever Aleud Warcaller attacks, harmonize. (Trigger up to one harmony of a permanent you control.)