msem-instigator

Flying
As long as Aerial Tactician is tapped, Soldiers you control get +0/+1.
As long as Aerial Tactician is untapped, Soldiers you control get +1/+0.

{T}, Discard a card: Draw a card from each of your libraries.
{1}{U}{R}, {T}, Discard your hand: Return each Study card from your graveyard to your hand.

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.

Flash
When you cast Aether Ascendant, you may have it become a copy of target instant or sorcery spell. If you do, choose new targets for it. (It won't enter.)

Spells you cast from anywhere other than your hand cost {1} less to cast.
Whenever an opponent casts a spell with the same name as a card they own in exile or in their graveyard, that player loses 1 life and you gain 1 life.

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 Aether Road Caravan enters, gain control of target nonland permanent with mana value 3 or less for as long as you control Aether Road Caravan.

When Aether Sculptor enters, create a tapped colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

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.)

When Affluent Host dies, it deals 1 damage to each opponent. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
Foreshadow {2}{R} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

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 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.

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

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, haste
Whenever Aiel's Fury attacks, scry 2, then reveal the top card of your library. Aiel's Fury gets +X/+0 until end of turn, where X is that card's mana value.

Ainok Alpha can't be blocked by more than one creature.
Other Hounds you control get +1/+1 and can't be blocked by more than one creature.

Whenever Ainok Caretaker or another Hound you control attacks, untap that creature and it gets +1/+1 until end of turn.

Trample
Other Hounds you control get +1/+1 and have trample.

Whenever another creature named Ainok Pack you control enters, you gain 2 life.

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.

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
When Aith Aera Sentinel enters, create a 1/1 green Elf creature token.

Whenever a creature token you control enters, put a +1/+1 counter on target creature you control.

Aurashaper and Aura spells you cast cost {1} less to cast.