msem-instigator

[+1]: Draw two cards. At the beginning of your next end step, discard your hand.
[–3]: You get an emblem with “At the beginning of your upkeep, put a loyalty counter on each Aerida planeswalker you control.”
[–5]: Take an extra turn after this one.

Enchant creature
When Aerie Watch enters, draw a card.
Enchanted creature gets +1/+1 and has reach.

Flying
Your opponents play with their hands revealed.
If an opponent would search their library for a card, you may have that player search their hand for that card instead.

If a creature entering the battlefield under your control causes a triggered ability of that creature to trigger, you may exile it. If you do, that ability triggers an additional time.

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).

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.

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.

{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.

As long as it's your turn, Ahl the Omenwing is a 2/1 Bird Wizard creature with flying and indestructible. (He doesn't lose loyalty while he's not a planeswalker.)
[+1]: Surveil X, where X is the number of creatures that attacked this turn.
[–2]: Return target nonland permanent to its owner's hand. Draw a card.

{T}, Discard a card: Add {C}.
Whenever you discard one or more cards, you may pay {2}. If you do, draw a card.

Enchant land
When Aid from Martoob enters, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)
When enchanted land is tapped for mana, add one mana of any color.

[+1]: Aiel Tazan deals 2 damage to any target. Then she deals 2 damage to herself unless you have her deal 2 damage to you.
[–3]: Creatures you control get +2/+0 and gain haste until end of turn.
[–X]: Create an X/1 red Elemental creature token with haste and trample. Exile that token at the beginning of the next end step. If X is 6 or more, it gains double strike.

[+1]: Exile up to one other target nonland permanent. As long as it remains exiled, its owner may pay {1} as a sorcery to put it onto the battlefield.
[–3]: Choose 0, 1, or 2. Each player sacrifices that many creatures.
[–4]: You get an emblem with “If a nonland, nontoken permanent would enter and it wasn't cast, you may exile it instead.”

Whenever one or more counters are put on a permanent you control for the first time each turn, create that many 1/1 green Squirrel creature tokens.
{1}{G}{W}, {T}: Proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Frenzy 2 (Whenever this creature attacks and isn't blocked, it gets +2/+0 until end of turn.)
Whenever Airam, Packleader becomes blocked, other creatures you control get +1/+1 until end of turn.

As long as Ajani Enlightened has an odd or even number of loyalty counters on him, he has protection from mana values of that quality.
[+1]: Any number of players may draw a card. You may put a loyalty counter on Ajani Enlightened for each opponent that does.
[0]: You gain 2 life. Untap up to two target lands.
[–8]: Create a 5/5 white Avatar creature token with protection from odd mana values and a 5/5 white Avatar creature token with protection from even mana values.

[+1]: Distribute two +1/+1 counters among up to two target creatures. You gain 2 life.
[–1]: Create a 2/2 green Cat Warrior creature token.
[–3]: Exile target creature. Its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle.
[–7]: You get an emblem with “Creatures you control get +X/+X, where X is your life total.”

[0]: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
[–2]: Exile target creature. Create a battle token with three defense and “When this battle leaves the battlefield, return the exiled card to the battlefield under its owner's control.” You're protecting it.
[–5]: Create two 0/0 black Phyrexian Germ creature tokens, then put two +1/+1 counters on each creature you control.

This spell can't be countered.
Flying
Whenever Ajax, Tyrant of the Empire enters or deals combat damage to a player, draw a card.
Whenever Ajax or another Dragon you control attacks, that Dragon deals 2 damage to any target.