msem-instigator

When Smokeweaver Initiate dies, draw a card.

When Sofia's Swashbucklers enters, you may return target card with foretell from your graveyard to your hand.

Flying
When Spawn of Keranos enters, you may draw a card. If you do, discard a card unless you control another creature with flying.

Whenever Starlight Emissary harnesses a spell, draw a card.

Flying
Augmented — Whenever Station Repair Technician enters or attacks, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, creatures you control gain flying until end of turn.

You may reveal the second card you draw each turn as you draw it. When you do, create a 2/2 blue Avatar Wizard creature token with prowess if it's a creature card. If it's a land card, create a Treasure token. If it's a noncreature, nonland card, Steward of Second Sphere can't be blocked this turn.
{3}{W/U}{W/U}: Scry 2.

Flying, prowess
Whenever Surveyor of Skies attacks, you may return a permanent you control to its owner's hand.

Valdez's Strike Leader can't be blocked if you have more cards in hand than defending player.

Whenever Wadepool Frog attacks, it gains flying until end of turn.

Flash
Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)

When Whisper Witch enters, choose up to one target creature. That creature's controller mills four cards, then puts that creature on top of their library.

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.