msem-instigator

Flying
When Ancient of Reflections enters, create a token that's a copy of target creature you control not named Ancient of Reflections, except it's 1/1 and has haste. Sacrifice it at end of turn.

When Ancient of the Glade enters, put a +1/+1 counter on each other creature you control.
{2}, Remove a +1/+1 counter from a creature you control: That creature gains indestructible until end of turn.

When Andazir Veteran enters, amass Soldiers 2. (Put two +1/+1 counters on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

Return target creature card from your graveyard to the battlefield. If it's an Azra or Demon, you gain 3 life.

Flying, vigilance
At the beginning of your upkeep, if you control four or more Plains, put a +1/+1 counter on each other creature you control.

Flying
Whenever you cast a spell from anywhere other than your hand, you may choose one —
• Draw a card, then discard a card.
• Angel of Wisdom phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Converge — You draw X cards and gain X life, where X is the number of colors of mana spent to cast Animus Vox.

Flying, vigilance
Augmented — When Antigravity Agent enters, if you've spent {W}{U}{R}{B}{G} to cast spells this turn, distribute a flying counter and a vigilance counter among one or two creatures you control.

This spell costs {1} less to cast for each storied permanent you control. (Enchantments and legendary permanents are storied.)
Counter target spell.
Draw a card.

Creatures you don't control get -1/-1.
Mirage {1}{B} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Antu, Sun Spirit can't attack or block unless you control ten or more permanents.
As long as it's your turn, other creatures you control get +X/+0 and have haste, where X is the amount of life you've gained this turn.
When Antu dies or is put into exile from the battlefield, you may put him into his owner's library third from the top.

Vigilance, trample
Whenever another Horror you control enters, choose one —
• Destroy target artifact or enchantment.
• You gain 4 life.
• Apex Abomination fights another target creature.

Apothecary's Gift deals 5 damage to target creature or planeswalker. You gain life equal to the excess damage dealt this way.

At the beginning of your end step, put an encroachment counter on Approach of Old Lovi, then it deals X damage to any target and you gain X life, where X is the number of encroachment counters on Approach of Old Lovi.

Flash
Flying
As long as an opponent controls more creatures than you, Arbiter of the Scales gets +2/+2 and has first strike and lifelink.

Trample
When Arborback Stomper enters, you gain 5 life.

Whenever you cast an instant or sorcery spell, you may pay {1}. If you do, choose one—
• Draw a card, then discard a card.
• Tap target creature.
• Target creature gains flying until end of turn.
• Target player mills two cards.

Flying
When Arcanum Owl enters, you may return target instant or sorcery card from your graveyard to your hand.

Flying, trample
Once each turn, when you cast a spell from anywhere other than your hand, you may copy it. If you do, you may choose new targets for the copy.

Create three 2/2 green Wolf creature tokens.

Flying
Whenever a creature you control phases in, it gains flying until end of turn.

Trample
When Arpechian Bellowers enters, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Search your library for a green creature card, reveal it, put it into your hand, then shuffle.

Trample
When Arpechian Yatte enters, put a +1/+1 counter on each other creature you control.
Whenever another creature you control enters, put a +1/+1 counter on Arpechian Yatte.

If a player would draw a card, instead that player may put a card they own exiled with Arroyo, the Bound into their hand.
{3}: Search target player's library for a card and exile it face down, then that player shuffles. They may look at that card for as long as it remains exiled.

Draw two cards. You may cast an instant or sorcery spell with mana value X or less from your hand without paying its mana cost, where X is the number of cards in your hand.