msem-instigator

Whenever a creature you control is dealt damage, put a +1/+1 counter on that creature.

When Uncovered Mine enters and at the beginning of your upkeep, return a random card from your graveyard to your hand.

When Uncovered Secrets enters, search your library for an artifact card, reveal that card, then shuffle and put that card on top.
Concord — Creatures you control get +1/+1 as long as there are four or more card types among permanents you control.

When Undead Archivist enters, return target instant or sorcery card from your graveyard to your hand.
Revive {5}{U} ({5}{U}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

When Undead Banneret enters, if you control a legendary creature, each opponent loses 4 life.

Creature cards in your graveyard have revive {2}{B}{B}. ({2}{B}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Concord — As long as there are four or more card types among permanents you control, you may cast the first spell you cast each turn without paying its mana cost.

Vigilance
Whenever Underpass Sentinel enters or attacks, you may put a +1/+1 counter on another target creature you control without one.
Sacrifice Underpass Sentinel: Embattled creatures you control gain hexproof and indestructible until end of turn. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

When Undying Lich dies, create a 6/3 black Zombie Horror creature token with menace and “When this creature dies, create an 8/5 black Elder Demon Horror creature token with flying, deathtouch, and menace.”

When Undying Watcher enters, germinate. (Put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)
Sacrifice another creature: Undying Watcher gains indestructible until end of turn.

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.)

Unearthed Legion's power and toughness are each equal to the number of cards in your graveyard.
At the beginning of your upkeep, mill a card.

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.

Create three 1/1 colorless Servo artifact creature tokens.
Exile Unending Armies. At the beginning of your upkeep, if you have more life than each opponent, you may cast it without paying its mana cost. Otherwise, put it into your graveyard.

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

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

Search your library for a card, reveal it, then shuffle and put that card on top of it. If you revealed a noncreature card this way, each opponent loses 2 life and you gain 2 life.

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

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

If you would draw a card, you may return an instant or sorcery card from your graveyard to your hand instead.
{U}: Draw three cards.

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

When Unity Spheres enters, create two 1/1 colorless Construct artifact creature tokens.
Tap two untapped creatures you control: Add two mana of any one color.

Target player loses 3 life.

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Unleash the Dragon deals 1 damage to any target for each spell cast this turn.