msem-instigator

Create a 2/2 black Zombie creature token, then sacrifice a creature.

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Return up to two target creature cards from your graveyard to your hand. You lose 2 life.

Whenever a creature you control dies, you may return all cards that were inscribed onto that creature and all Auras that were attached to that creature to their owners' hands.

Unending Slime enters with X +1/+1 counters on it.
{2}{G}{G}{G}: Return Unending Slime from your graveyard to your hand.

Enchant creature you control
Enchanted creature gets +1/+1.
When enchanted creature dies, return it to the battlefield under your control, then arm it. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)

Surveil 1, then draw a card.
Flashback—{2}{B}, Pay 1 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Target creature you control explores. Then it fights up to one target creature you don't control. If that creature has flying, the creature you control deals damage equal to its power to it instead. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then you may put that card in your graveyard.)

Search your library for up to four basic land cards, reveal them, put them into your hand, then shuffle. You may play an additional land this turn.

Flying, vigilance
When you attain Unfallen Angel, target opponent discards a card.

Flying
When Unfettered Atrocity enters, destroy target creature or planeswalker.

Unfettered Noble can't be blocked unless defending player pays 3 life, discards a card, or sacrifices a nonland permanent for each creature they control that's blocking it.
Sacrifice a nonland permanent: Unfettered Noble gains indestructible until end of turn.

Exile target nonland permanent if its mana value is less than or equal to the number of creatures you control.
Lifecycle {3} ({3}, Discard this card: Create two tapped 1/1 colorless Elemental creature tokens.)

Ungoverned Sneak can't be blocked by creatures with greater power.
Attain {3}{U} ({3}{U}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Return target creature card from your graveyard to your hand.
Inscribe {3}{B} ({3}{B}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

As an additional cost to cast this spell, exile X cards from your graveyard.
Create X tapped 2/2 black Zombie creature tokens.

Menace
{3}{B}, Discard a card: Unhallowed Singers gets +3/+0 until end of turn. Whenever it deals combat damage to a player this turn, they discard a card.

Destroy target creature with total power and toughness 8 or less.

Starting with you, each player may sacrifice a creature. Each player that doesn't loses life equal to the total power of creatures sacrificed this way.

Target creature can't block until end of turn. If that creature had a Steed attached to it, unattach that Steed and it can't block until end of turn.
Draw a card.

{T}: Add one mana of any color.
{T}, Sacrifice Unicorn of the Vale: Add three mana of any one color.

Whenever you cast a noncreature spell, create a 1/1 colorless Construct artifact creature token.

Look at the top six cards of your library. Put up to two creature cards with mana value 3 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order. Then you gain 1 life for each Angel, Demon, Faerie, and/or Spirit you control.

Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
United Patrol can block an additional creature each combat.