msem-instigator

As long as Sewer Pack is on the battlefield, you may cast spells named Sewer Pack from your graveyard.
Sewer Pack gets +1/+1 for each other creature on the battlefield named Sewer Pack.

Flying, haste
Ride {1}{R} ({1}{R}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Magma Bolt deals 2 damage to any target. If a creature dealt damage this way would die this turn, exile it instead.

At the beginning of combat on your turn, create a 1/1 red Nomad creature token with haste.
At the beginning of your upkeep, if you control five or more creatures, you may transform Emerabi and Sunnula.

Creatures you control with flying get +1/+1.

Vigilance
Whenever another creature you control enters, scry 1.
{T}: Reveal the top card of your library. If it's a creature card, put it into your hand. Otherwise, you may put it into your graveyard.

[+1]: Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.
[+1]: Until end of turn, Lucien, the Grifter becomes a legendary 3/3 black and red Human Warrior creature with deathtouch, lifelink, and indestructible.
[–3]: Exile target artifact or creature. You gain life equal to its mana value.

If you would create a token, you may instead create a tapped 2/2 green Faerie Bard creature token.
Whenever one or more creature tokens you control deal combat damage to a player, that player sacrifices an artifact or enchantment.

At the beginning of your upkeep, create a 1/1 white Soldier creature token.
{1}{G}{W}: Create a 1/1 white Soldier creature token. Activate only during your upkeep and only if Faith is in your graveyard.

Harmony — Target player mills four cards.
When Creeping Pianist enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Reach (This creature can block creatures with flying.)
Whenever a creature you control enters for the first time each turn, untap Skittering Swarm. It gets +1/+1 until end of turn.

Other enchantment creatures you control get +1/+1.
As long as you control three or more enchantment creatures, if a triggered ability of an enchantment you control would trigger, that ability triggers an additional time.

When Ichi-no-Oni enters, each player loses 2 life.

You draw two cards and you lose 2 life. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Flying
{B/G}, Discard a creature card: Badru, the Skyshadow becomes a copy of the discarded card until end of turn, except he has flying and is 5/5.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Return target creature card with mana value 2 or less from your graveyard to the battlefield.
II — Each opponent loses 2 life and you gain 2 life.
III — Return target creature card with mana value 2 or less from your graveyard to the battlefield.

Wanderlust — When Riftbreaker Mage dies, if you control four or more differently named lands, Riftbreaker Mage deals damage equal to its power to each opponent.

When Ravenous Abomination enters, choose one —
• Create two Treasure tokens.
• Put a +1/+1 counter on Ravenous Abomination.

Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Counter target spell unless its controller pays {3}. That spell's controller mills three cards.

When Soulcarver enters, destroy up to one target non-Demon creature. If you do, create a 2/2 black Demon creature token and draw a card.

Flying
Whenever Aether Crosser attacks, you may aetherize another target tapped creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)
Crew 1

When Gleamhorn Gargantuan enters, put a +1/+1 counter on up to one other target creature.
Cycling {2} ({2}, Discard this card: Draw a card.)

At the beginning of your upkeep, mill two cards.

Counter target spell. For each other card named Overcharge in your graveyard, create a colorless Canister artifact token with “{T}, Sacrifice this artifact: Add {C}.”