msem-instigator

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.

[+1]: Add {W}{U}{B}{R}{G}.
[–1]: Exile the top three cards of your library. Until end of turn, you may play cards exiled with this permanent.
[–3]: Create a 5/5 Archon creature token that's all colors and has flying and “When this creature enters, it deals 5 damage to any target.”

Creatures you control have trample, haste, and hexproof.
{2}{G}{G}: Create a 2/2 white Cat creature token.

At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.

Create a 1/1 white Spirit creature token with flying. (Then exile this card. You may cast the artifact later from exile.)

The Urchin King's power and toughness are each equal to the number of cards in all graveyards.
Sacrifice a creature: The Urchin King gains lifelink and indestructible until end of turn.

Each creature you control enters with an additional +1/+1 counter on it.
Each planeswalker you control enters with an additional loyalty counter on it.

Tap target creature. If you control a Monk, draw a card. (Then exile this card. You may cast the creature later from exile.)

Return target permanent you control to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Enchant creature
Enchanted creature gets +3/+3 and has trample.

Search your library for a creature card, reveal it, then shuffle and put that card second from the top.

Draw a card. (Cast a copy of this spell once while this creature is on the battlefield.)

Each player sacrifices a creature. (Then exile this card. You may cast the artifact later from exile.)

(Transform this if it's not attached to a creature. Pay {2}{W} as a sorcery to unattach it.)
Enchant creature you control
Trusty Steed's rider gets +2/+2.

Hexproof
Whenever this creature transforms into Tsunami Titan or attacks, you may return target creature to its owner's hand.

Target player loses 3 life and you gain 3 life. (Then exile this card. You may cast the creature later from exile.)

Trample, haste
When Tyrants of Bundan enters, tap all lands target player controls. They don't untap during their controller's next untap step.

Target creature gets -5/-0 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Unbound Spirit can't be blocked.
When you attain Unbound Spirit, tap target creature. That creature doesn't untap during its controller's next untap step.

Enchant creature
Enchanted creature has first strike. (That creature deals combat damage before creatures without first strike.)

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

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.

Until end of turn, you can't lose the game, your opponents can't win the game, and your life total can't change.

Other creatures you control get +1/+0.
At the beginning of combat on your turn, create a 1/1 red Human creature token with haste.

Unvirtuous Maestro can't be blocked except by three or more creatures.