msem-instigator

When Aethermancer's Companion enters, aetherize up to two other non-Cat permanents you control. (Create tokens that are copies of each of them, then exile them.)
Recite {5}{W}{U} (You may cast this spell from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

Flash
When Aethermancer's Familiar enters, at the beginning of the next end step, you may aetherize target creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)

Equipped creature gets +2/+1.
Equip multicolored creature {1}
Equip {2}

At the beginning of your end step, you lose 3 life unless you sacrifice a creature.

Flash
If you would upgrade a creature you control, you may put a +1/+1 counter on it instead.
{3}{U}: Put a +1/+1 counter on Affluent Cetanthrope and draw a card.

When Affluent Knight enters, recruit, then recruit again. (To recruit, create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

When Aftermath of the Surge enters, create two Treasure tokens.
{1}{U}, Sacrifice two artifacts: Draw two cards.
{3}{U}, Sacrifice four artifacts: Create an 8/8 blue Kraken creature token. It can't block this turn.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Scry 2.
II — Draw two cards.
III — Spells you cast this turn cost {2} less to cast.

When Ageless Ascetic enters, return up to one target instant or sorcery card from your graveyard to your hand.

Flying
When Ageless Lorekeeper enters, you may discard your hand. When you do, draw three cards.

Whenever a land you control enters, untap Ageless Wanderer.
{1}, {T}: Add one mana of any color.

When Ageless Weaver enters, create a green Aura enchantment token named Years of Experience attached to target creature. The token has enchant creature and “Enchanted creature gets +2/+2.”
Whenever an enchanted creature you control dies, create a 3/3 green Elemental creature token.

Improve {1} ({1}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Once each turn, when one or more counters are put on a permanent you control, create a 1/1 colorless Human creature token.
Whenever you attack with three or more creatures, destroy up to one target artifact or enchantment.

Whenever a creature you control dies, put a +1/+1 counter on Agent of Andazir.

Flash
When Agent of Deception enters, counter target creature or planeswalker spell unless its controller pays {X}, where X is your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Flash
When Agent of Equilibrium enters, destroy target creature or planeswalker an opponent controls that was dealt damage this turn.

Deception {2}{B} ({2}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Agent of Long Shadows deals combat damage to a player, you may put a Rogue card from your hand or graveyard onto the battlefield.

Whenever Agent of Vitu-Ghazi deals combat damage to a player, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Menace, trample, indestructible
Whenever Aghavaan Unleashed deals combat damage to a player, that player gets that many poison counters.
At the beginning of your end step, sacrifice another creature or transform Aghavaan Unleashed.

Poisonous 1 (Whenever this creature deals combat damage to a player, that player gets a poison counter.)
At the beginning of your upkeep, destroy target artifact or enchantment if its controller is poisoned.

{T}: Add {C}.
At the beginning of each end step, if you control five or more Snake creatures, transform Aghavaan's Wound.

At the beginning of your first main phase, exile target card in a graveyard. If it's a creature card, put a +1/+1 counter on target creature you control. If it's a land card, add {C}. If it's a noncreature, nonland card, you gain 3 life.

I, II — Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Discovery — {4}: You gain 2 life.

Deception {1}{B}
When Aguri, Shadow of Doubt enters, target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

[+2]: Create a 1/1 blue Bird creature token with flying.
[–2]: Reveal the top card of your library. If it's an enchantment or land card, put it onto the battlefield. Otherwise, put it in your hand.
[–7]: Draw seven cards.