msem-instigator

Reverberate {2}{R} (When you cast this spell, copy it if you paid its reverberate cost.)
Creatures your opponents control get -2/-0 until end of turn. If Unstable Experiment is reverberated, creatures you control get +1/+0 until end of turn.

You may have Unstable Impersonator enter as a copy of any creature on the battlefield chosen at random.

Menace
Unveil {3}{B}{R} ({3}{B}{R}: Transform this. Unveil only as a sorcery.)

Return target creature card from your graveyard to the battlefield with an additional -1/-1 counter on it.

Unstoppable Slaughter deals 1 damage to each creature and each player. Whenever a creature dealt damage by Unstoppable Slaughter this turn dies this turn, repeat that process.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Unstoppable Weed gets +1/+1 for each +1/+1 counter on other creatures you control.

Choose one, then choose another for each card named Unsuspecting in your graveyard.
• You may return a permanent you control to its owner's hand.
• You may put an artifact, creature, or land card with mana value 2 or less from your hand onto the battlefield.
• Untap up to three target permanents.
• You gain 4 life.

Target creature you control gets +1/+0 until end of turn. That creature deals damage equal to its power to another target creature.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever a creature you control becomes renowned, create a 1/1 red Soldier creature token with haste.

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

For each land you control, you may return a land card from your graveyard to the battlefield tapped.

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

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

When Unwitting Fanatic enters, create a 3/2 colorless Horror creature token.
Sacrifice Unwitting Fanatic: Another target permanent you control gains hexproof and indestructible until end of turn.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Menagerie — When Uplifting Companion enters, 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 {6}{W}{W}. If you do, it enters 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.

Constructs you control have haste.
When Urak, Voice of the Horde or another Construct you control enters, creatures you control get +1/+0 until end of turn.
Respawn (When this creature dies, if it attacked this turn, return it to its owner's hand.)

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.

When Urn of Heroes enters, you may search your library for a legendary card, put that card into your graveyard, then shuffle.
{T}: Add {C}.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
When Ushi Yun enters, create an Idol token.
As long as you're in a renaissance, artifacts you control have “{T}: Draw a card.”

Draw two cards, then you may foretell a card with foretell from your hand. It costs {0} to foretell this way. You lose 2 life. (You don't reveal that card. You can't foretell cards without foretell in this way.)

Deception {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Unblocked attacking creatures you control get +1/+0.

Other legendary creatures you control get +1/+1.
At the beginning of your upkeep, you may search your library for a legendary card, reveal that card, and put it into your hand. If you do, you skip your draw step this turn and shuffle.

Valdez's Strike Leader can't be blocked if you have more cards in hand than defending player.