msem-instigator

Create an 8/8 blue Kraken creature token with hexproof.
Rerun (If you cast this from your hand, exile it as it resolves. Whenever a creature you control dies, you may cast this card from exile without paying its mana cost.)

Flying
When Apogee Cranes enters the battlefield, 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.”)

Apostle of the Elders has lifelink as long as it has a +1/+1 counter on it.

Whenever Apostle of the Spirit Moon becomes blocked by a creature, Apostle of the Spirit Moon deals 1 damage to that creature and that creature's controller.

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

Target creature gets -3/-2 until end of turn.

At the beginning of your upkeep, if you control ten or more storied permanents, you win the game. (Enchantments and legendary permanents are storied.)

Escalate {2} (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Search your library for a card, put it into your hand, then shuffle.
• Return target card from your graveyard to your hand.
• Add {B}{B}{G}{G}.

You may look at an additional card each time you scry.
{2}, Tap two untapped creatures you control: Scry 1.

Target creature you control deals damage equal to its power to target creature or planeswalker you don't control.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “III—You may cast a copy of this card from exile without paying its mana cost.”)

Whenever Apprehensive ‘Slinger deals combat damage to a player or planeswalker, you may discard a card. If you do, draw a card.

When Apprentice Summoner enters the battlefield, search your library for a creature card with mana value 1 or less, put it onto the battlefield, then shuffle.

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.

As Approach the Dark Tomb enters the battlefield, choose life or death.
• Life — Whenever you cast a creature spell, you may pay 1 life. If you do, draw a card.
• Death — Whenever a creature you control dies, you may pay 1 life. If you do, draw a card.

Enchant artifact or creature
At the beginning of each upkeep, if enchanted permanent is tapped, untap it.
You control enchanted permanent.

When Appropriated Gear enters the battlefield, create a Treasure token.
Equipped creature gets +1/+1.
Equip {2}

Counter target spell. Draw a card, then discard a card.

Target creature gets +2/+2 until end of turn. If it's an enchanted creature or enchantment creature, it also gains hexproof and indestructible until end of turn. (It can't be the target of spells or abilities your opponents control. Damage and effects that say “destroy” don't destroy it.)

As Aquatic Refuge enters the battlefield, you may tap an untapped creature you control. If you don't, Aquatic Refuge enters the battlefield tapped.
{T}: Add {W} or {U}.

{U}: Aqueous Treader gets +1/-1 until end of turn.
{U}: Aqueous Treader gets -1/+1 until end of turn.

Other creatures you control can't attack or block alone.

At the beginning of your upkeep, you may pay {1}{G/U}. If you do, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)
At the beginning of your end step, you may pay {1}{G/U}. If you do, populate. (Create a token that's a copy of a creature token you control.)

Flying, lifelink
Improve {1}{W/B} ({1}{W/B}: 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 you gain life, you may have each opponent lose 2 life.

Whenever you foretell a card or cast a foretold spell, each opponent loses 1 life and you gain 1 life.

Whenever Aravant Smuggler deals combat damage to an opponent, if it's embattled, draw a card. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)