msem-instigator

Whenever you make first contact, you may draw a card. If you do, put a card from your hand on the bottom of your library. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Flash
Enchant permanent or spell
Whenever enchanted permanent or spell deals damage to a creature, return that creature to its owner's hand (if it's still on 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.)

Return target spell or creature to its owner's hand.
Quickdraw {U} (When a creature you control blocks or becomes blocked, you may cast this spell for {U}.)

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 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.

Take an extra turn after this one. Exile Again.
Fuse (You may cast one or both halves of this card from your hand.)

Target player mills X cards, where X is the number of cards named Against the Waves in your graveyard. Draw a card, then conjure three cards named Against the Waves and shuffle them into your main library.

(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.

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.)

Draw a card.
Showcase {3}{U} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Flying
Whenever Albino Drake deals combat damage to an opponent, 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.”)

When Alchemist's Kit enters, you may return target creature to its owner's hand.
2U, Sacrifice Alchemist's Kit: Draw a card.

Flying
Whenever a creature enters under an opponent's control, you may pay {1}{B}. If you do, 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.)

Converge — Gain control of up to X target creatures with total mana value X or less, where X is the number of colors of mana spent to cast Alive and on Top.

You may cast this spell without paying its mana cost if it targets a spell you control.
You may choose new targets for target spell.

When Allagras' Vanguard enters, create two 1/1 blue Merfolk creature tokens with “When this creature dies, draw a card, then discard a card”.

[+1]: Create a 1/1 blue Merfolk creature token with “When this creature dies, draw a card, then discard a card.”
[–1]: Target creature gets -2/-0 until your next upkeep and attacks during its controller's next turn if able.
[–7]: You get an emblem with “Creatures your opponents control get -4/-0 and attack each turn if able.”

This spell costs {1} less to cast for each artifact you control.
Draw two cards.

Whenever Almgrove Ambassador blocks or becomes blocked, you may untap target creature and remove it from combat.

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
Enchanted creature loses all abilities except for mana abilities.

Flying
Whenever an artifact you control leaves the battlefield, scry 1.

Whenever Alrathan Scholar deals combat damage to a player or planeswalker, draw a card.
{2}{U}: Target creature gains flying until end of turn.

Target player mills five cards.
Draw a card.

Bleed {1}{U} (You may cast this spell for its bleed cost if an opponent has lost life this turn.)
Draw two cards.