msem-instigator

Frenzy 2 (Whenever this creature attacks and isn't blocked, it gets +2/+0 until end of turn.)
Blocked creatures you control have first strike.

{2}: Avaricious Ghul gets +1/+1 until end of turn. If mana from a Treasure was spent to activate this ability, put a +1/+1 counter on Avaricious Ghul instead.

Flying
Harmony — Until the end of your next turn, you may cast target instant or sorcery card from your graveyard. If that card would be put into your graveyard, exile it instead.
When Aven Acoustimancer enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Flying
When Aven Merchant enters, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Flying
When Aven Strategist enters, return up to one target creature to its owner's hand.

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | For each permanent type, return a card of that type from your graveyard to your hand. Exile Awaken Ancestry.
5 | Return an instant card and a sorcery card from your graveyard to your hand.

Pressure {3}{B}{B} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Each player sacrifices a creature. Put a creature card from a graveyard onto the battlefield under your control.

Equipped creature gets +3/+2.
Whenever a land you control enters, you may attach Axe of the Crann to target creature you control.
Equip {4}

When Ayala's Blessing enters, put a +1/+1 counter on up to two target creatures.
Whenever an embattled creature you control dies, you may return it to its owner's hand. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

The first instant or sorcery spell you cast each turn has convoke. (Each creature you tap while casting that spell pays for {1} or one mana of that creature's color.)

Azun's Play deals damage to any target equal to the number of cards in your hand.
Quickdraw {R}{R} (When a creature you control blocks or becomes blocked, you may cast this spell for {R}{R}.)

When Azure Archaeologist enters, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
{2}, {T}, Sacrifice a Clue: Draw two cards, then discard a card.

Flying, trample
Prismatic — Whenever you cast a multicolored spell, put a +1/+1 counter on Azure Caterwauler.

Draw X cards, where X is the number of differently named lands you control.

Whenever Babbling Experiment or another creature you control enters, target player mills two cards.

First strike
Back-Alley Gnoll has lifelink as long as it's enchanted by a black Aura.
Back-Alley Gnoll gets +2/+0 as long as it's enchanted by a red Aura.

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.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever Backalley Silencer deals combat damage to a player, destroy target marked creature.

Deathtouch
When Backstage Comic enters, target player discards a card.

Lifelink
At the beginning of your end step, if you gained life this turn, put a +1/+1 counter on Backstage Manager.

When Backstage Tinkers enters, you may return an artifact card from your graveyard to your hand.

Menace, haste

(Transcend as a sorcery to gain that type and a +1/+1 counter.)
Flying
{1}{W}: Demigod — Return up to one target creature card with mana value 2 or less from your graveyard to the battlefield.
{3}{W}: God — Put a +1/+1 counter on each creature you control with the least power among creatures you control.

Menace
As long as Balefire Harbinger is attacking, creatures in its pack can't be blocked unless defending player pays {1} and 1 life for each creature they control that's blocking one of those creatures. (Two or more creatures you control with equal power are in a pack.)

Flying, deathtouch