msem-instigator

Lifelink
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Spoiled Oracle mentors a creature, that creature gains lifelink until end of turn.

Flying
{B}, Sacrifice another creature: Draw a card.

Flying
Whenever a creature dealt damage by Subturgian Legionnaire this turn dies, create a 1/1 black Vampire creature token with lifelink.

Primal {1}{G}{G} (During your turn, you may cast this spell for {1}{G}{G} instead of playing a land.)
When Swampedge Sentinel dies, return another creature card from your graveyard to your hand.

Flying
Other Vampire creatures you control get +1/+0 and have menace.

Advance {3}{B}{B} (Cast this for {3}{B}{B} to advance it as it enters. {3}{B}{B}: Advance this as a sorcery.)
Whenever Tireless Archivist advances, search your library for a card, put it into your hand, then shuffle.

Flying
When Tormentor Harpy enters, if there are three or more creature cards in your graveyard, target creature an opponent controls gets -3/-3 until end of turn.

Whenever Toxic Lurker attacks, you may have target creature defending player controls get -2/-1 until end of turn.

When Trenchbottom Mariners enters, you lose 3 life, mill three cards, and create a Treasure token.
Whenever Trenchbottom Mariners attacks, you may cast a permanent card from your graveyard by sacrificing another artifact in addition to paying its costs.

Whenever a creature dealt damage by Truth Extractor this turn dies, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Whenever one or more other nontoken creatures die, create a Food token. (It's an artifact with “{2}, {T}, Sacrifice this artifact: You gain 3 life.”)
Whenever you sacrifice a Food, create a 1/1 black Bat creature token with flying.

Flying
Once each turn, when a creature an opponent controls dies, you may create a Treasure token.
{3}{B/R}{B/R}: Search target opponent's library for a card and exile it face down. Then that player shuffles. You may look at and play that card for as long as it remains exiled. Activate only once each turn and only as a sorcery.

Flying
Whenever you attack with two or more creatures with flying, each opponent discards a card.

Advance {5}{B}{B} (Cast this for {5}{B}{B} to advance it as it enters. {5}{B}{B}: Advance this as a sorcery.)
Whenever Well-Oiled Sniper advances, target creature gets -3/-3 until end of turn.

When Whistling Blades enters, you may destroy target creature or planeswalker.
Recite {1}{B}{B} (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.)

Wraith of the Fens gets +2/+2 as long as you've gained life this turn.

Flying
Assault {2}{B} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Wretched Lammasu assaults, each opponent discards a card.

Menace
When Zygos's Decimators enters, put a number of +1/+1 counters on it equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Haste
Whenever two or more creatures you control deal combat damage to a player, tap those creatures, then gain control of target creature you don't control until end of turn. Untap that creature. It gains haste until end of turn. After this phase, there's an additional combat phase.

Flying
When Ancient of Reflections enters, create a token that's a copy of target creature you control not named Ancient of Reflections, except it's 1/1 and has haste. Sacrifice it at end of turn.

Whenever an artifact or enchantment you control enters, Armament Scavenger gets +1/+0 and gains trample until end of turn.

Prowess
When Arms Tinkerer enters, choose one —
• Destroy target artifact.
• Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

First mate — Twelve or more cards in your starting deck are Dragons or have “Dragon” in their printed rules text. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Dragon spells you cast cost {1} less to cast.
Whenever Ashe attacks, it deals X damage to any target, where X is the number of Dragons you control.

Menace
Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Exile the top card of your library. You may play that card this turn.
[Lore III] Remove all lore counters from
Astral Cerberus. It deals 3 damage to up to one target creature.

Menace
Whenever Auros, Flame-Cursed attacks, it deals 3 damage to each opponent.