msem-instigator

Target attacking creature gets +1/+0 until end of turn. When that creature dies this turn, it deals damage equal to its power to defending player.

Menace (This creature can't be blocked except by two or more creatures.)
Engage (This creature must be blocked each combat if able.)

Untrekked Territory enters the battlefield tapped.
{T}: Add {B} or {G}.
When Untrekked Territory enters the battlefield, you may put a loyalty counter on a planeswalker you control.

Look at target opponent's hand, then fateseal 1. (To fateseal 1, look at the top card of an opponent's library, then you may put it on the bottom of that player's library.)

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

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.)

Unwavering Questant can't block.
When an opponent fails a trial, return Unwavering Questant from your graveyard to the battlefield.

When Unwavering Sentinel enters the battlefield, for each creature you control, create a white Aura enchantment token named Shield with “Enchant creature” and “If enchanted creature would be destroyed, instead remove all damage from it and sacrifice this Aura” attached to that creature.

Gain control of target creature until end of turn. Untap that creature. It gains haste and is marked until end of turn.

Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Attain {3}{W} ({3}{W}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Choose one —
• Unwrite deals 3 damage to target attacking or blocking creature.
• Destroy target artifact.
• Destroy target enchantment.

Ward {1}
Other Scouts you control get +1/+1.
Whenever three or more Scouts you control attack, draw a card.

Target creature gets -9/-0 until end of turn. 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.”)

Distribute two +1/+1 counters among one or two target creatures.

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

At the beginning of each combat, harmonize twice. (To harmonize, trigger up to one harmony of a permanent you control.)
Harmony — Target creature gets +1/+1 and your choice of flying, haste, or vigilance until end of turn.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Menagerie — When Uplifting Companion enters the battlefield, if there are five or more creature types among creatures you control, up to two target creatures you control gain flying until end of turn.

Create a 2/2 white Angel creature token with flying.
Coalesce {6}{W}{W} (You may cast this from your graveyard for its coalesce cost. If you do, put it onto the battlefield as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Flying

Whenever a creature dies, you may pay 1 life. If you do, draw a card.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Exile target nonland permanent an opponent controls. If this spell was harnessed by a token, you gain 5 life.

All creatures have “When this creature enters the battlefield, destroy target creature with a lesser mana value.”

{4}{B}{B}: Return Urchin Defector from your graveyard to the battlefield transformed.

Menace

When Urisk Fiddler enters the battlefield, draw a card.

If you would create a token, you may instead create a tapped 2/2 green Faerie Bard creature token.
Whenever one or more creature tokens you control deal combat damage to a player, that player sacrifices an artifact or enchantment.