msem-instigator

If a creature would leave the battlefield this turn, exile it instead.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, target player sacrifices a creature.

Target creature gains double strike until end of turn.

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature gets +2/+2.
{1}{G}: Regenerate enchanted creature.

Target creature can't be blocked this turn.
Draw a card.

Target creature gets +1/+1 until end of turn. Untap that creature.
Fabled {2}{W} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

Winnow (Damage dealt to this creature also causes you to lose that much life.)
{2}{B}: Each creature blocking Arroyo's Servant gains winnow until end of turn.

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.

Arsenal Curator gets +1/+1 as long as you control a Plains.
{2}{W}: Untap target creature you control. It gets +0/+1 until end of turn.

Gain control of target creature with the least power among creatures on the battlefield, then invigorate 2. (Choose a creature with the least power among creatures you control and put two +1/+1 counters on it.)

Counter target spell unless its controller pays {1}. If you control an artifact, instead counter that spell unless its controller pays {4}.

The next time target creature would be dealt damage this turn, prevent all but 1 of that damage. Whenever that creature perseveres this turn, put a +1/+1 counter on it. (A creature perseveres when it survives damage.)

Enchant player
Enchanted player may play an additional land on each of their turns.
Enchanted player may play lands from their graveyard.

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Ash Breather deals combat damage to a player, you may discard a card. If you do, draw a card.

Whenever you cast an Inscription spell, you may choose target creature you control. If you do, as that Inscription resolves, exile it inscribed onto that creature instead of putting it anywhere else.

Equipped creature gets +2/+2.
Art of war — At the beginning of your end step, if equipped creature dealt damage to an opponent this turn, target nonbasic land an opponent controls doesn't untap during its controller's next untap step.
Equip {2}

Equipped creature gets +1/+0 and has deathtouch and “{T}: This creature deals 1 damage to target creature you don't control. Sacrifice Assassin's Shuriken.”
Equip {2}

Target player sacrifices an attacking creature.
Bulwark — That player sacrifices two attacking creatures instead if you control a creature with toughness 4 or greater.

Target creature gets -5/-0 until end of turn. Adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)

Vanishing 4 (This permanent enters with four time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Equipped creature gets +3/+3.
Equip {2}

First strike (This creature deals combat damage before creatures without first strike.)
When Attended Knight enters, create a 1/1 white Soldier creature token.

When Attuned Ancient enters, if you control a legendary creature, you may have Attuned Ancient deal damage equal to its power to target creature an opponent controls.

Tribute 3 (As this creature enters, an opponent of your choice may put three +1/+1 counters on it.)
When Atuum Serpent enters, if tribute was paid, it gains defender. (This effect lasts indefinitely.)

Counter target spell. If you are glorious, draw a card. (You are glorious as long as you have a glory counter.)

Augury Hydra enters with X +1/+1 counters on it.
When Augury Hydra enters, scry Y, where Y is its power, then draw Y cards.

When Auramancer enters, you may return target enchantment card from your graveyard to your hand.