msem-instigator

Choose two —
• Tap target creature.
• Untap target creature.
• Draw a card.

Menace (This creature can't be blocked except by two or more creatures.)
Whenever a creature you control deals combat damage to a player, you may have Aspect of Rage deal 1 damage to any target.

When Asphodel Gravedealer dies, choose one —
• Put a +1/+1 counter on target creature you control.
• Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Whenever a storied permanent you control enters, tap target creature an opponent controls. (Enchantments and legendary permanents are storied.)

Aspiring Dragon has flying and haste as long as you control another Dragon.
{2}{R}{R}: Aspiring Dragon gets +3/+0 until end of turn.

Rhapsody {3}{W}{W} (Pay {3}{W}{W} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Lifelink

Creatures with power greater than Aspiring Recluse's can't block it.
Whenever Aspiring Recluse deals combat damage to a player, you may pay {2}. If you do, transform it.

Vanguard — Whenever a creature you control attacks alone, it gets +1/+1 until end of turn.

Flash
When Assassin of Fahrib enters, choose one —
• Destroy target creature that was dealt damage this turn.
• Scry 2.

Target creature gets -3/-0 until end of turn. That creature's controller mills six cards.

Destroy target tapped creature.

Destroy target creature. Create a tapped Treasure token.

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

Create three 1/1 colorless Construct Actor creature tokens.

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.)

Exile target nonland permanent. For each of its colors, its controller creates a 1/1 colorless Spirit creature token.

Menace
Once during each of your turns, when you sacrifice a permanent, you may put a +1/+1 counter on Assimilated Runner.

When Assurance of Finality enters, you may discard a card. If you do, draw two cards.
{1}, Sacrifice Assurance of Finality: Creatures you control gain haste until end of turn.

Archive 3 (As this enters, shuffle the top three cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
Whenever you draw a card from the archived library, put the top card of your main library on the bottom of the archived library.
{R}: Exchange a card from the archived library with a card from your hand.

When Astute Prophet enters, draw a card. If you control a legendary creature, draw two cards instead.

When Astute Sceneweaver enters, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Whenever a land you control enters, you may pay {2}{G}. If you do, put a +1/+1 counter on Atdrik Ravager.

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}

Put a +1/+1 counter on target attacking creature.
Draw a card.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)