msem-instigator

Flying
When Blossoming Hatchling enters, create a Treasure token.

Menace
Whenever Aswaran Conquerer attacks, you may sacrifice a nonland permanent. If you do, creatures you control get +1/+1 and gain trample until end of turn.

{6}{U}: Brume Trench-Thrasher can't be blocked this turn. This ability costs {1} less to activate for each instant and sorcery card you own in exile and in your graveyard.

(As this Saga enters and after your draw step, ad a lore counter. Sacrifice after III.)
I, II — Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
III — You may sacrifice any number of artifacts. If you do, draw that many cards.

Search your library for a basic land card or Desert card, reveal it, put it into your hand, then shuffle.
Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

When this creature enters, target creature seeks secrets. (Give it that Oath Aura. Fulfill it by attacking with it and two or more other creatures to draw a card.)
Whenever you draw a card, each opponent loses 1 life and you gain 1 life.

At the beginning of your end step, you may put a progress counter on Custom Armaments.
[progress 1-3] Sacrifice Custom Armaments: Destroy target blocked creature.
[progress 4+] Sacrifice Custom Armaments: Exile up to two target blocked creatures.
Sacrifice CARDNAME: Exile up to two target blocked creatures.

Remove a -1/-1 counter from target creature. That creature gets +2/+2 until end of turn.

If you control an Angel, Demon, Faerie, or Spirit, draw a card.
Exile target nonland permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever one or more creatures you control survive damage, add a quest counter.
1 — You may put a creature card with mana value 2 or less from your hand onto the battlefield.
2 — Put two +1/+1 counters on target creature you control.
3 — Choose target creature you control. You draw cards equal to half that creature's power, rounded down.

Target permanent becomes a colorless Mountain land until the beginning of your next upkeep.

Death knell — You may sacrifice a nontoken creature. If you do, create a 3/3 black Spirit creature token. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
Creatures you control dying causes their death knell to trigger. (In addition to the normal death knell trigger.)

Lifelink
Whenever Operative BABY attacks or you cast a black or red spell, create a 1/1 blue Elemental creature token with flying.

Trample
Whenever Unstoppable Zealot deals damage to a player or noncreature permanent, you may put a land card from your hand or graveyard onto the battlefield.

{T}, Tap two other untapped creatures you control: Add two mana of any one color.

{T}: Add {C}.
{T}, Reappropriate: Add {B} or {R}. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)

When Steward of Empire's Cradle enters, you may search your library for a Discovery, Quest, or Saga card, reveal it, then shuffle and put that card on top.
Civilized — If an ability of an enchantment you control triggers, if you control an artifact, a creature and an enchantment, that ability triggers an additional time.

Put a +1/+1 counter on each of up to X target creatures.
Augmented — If you've spent {W}{U}{B}{R}{G} to cast spells this turn, instead put three +1/+1 counters on each of those creatures. They gain trample until end of turn.

Activated abilities you activate cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.
Attain {5}{U} ({5}{U}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

When Night Howlers enters, target opponent reveals three cards from their hand and you choose one of them. Exile that card until Night Howlers leaves the battlefield.

When Student of Secrets enters, fateseal 1. (Look at the top one cards of an opponent's library, then put any number on the bottom and the rest on top in any order.)

Trial 3 (As you cast this spell, an opponent of your choice may pay 3 life. If they don't, they fail the trial.)
Target creature gets -1/-1 until end of turn. If that creature's controller failed the trial, it gets -4/-4 until end of turn instead.

Whenever you cast a noncreature spell, Novice Pyromancer deals 1 damage to target player or planeswalker.

Target creature you control gets +3/+0 and gains lifelink and indestructible until end of turn.

Primal {B}{B} (During your turn, you may cast this spell for {B}{B} instead of playing a land.)
Search your library for a card and put that card into your hand, then shuffle. Exile Deceitful Tutor.