msem-instigator

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

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.

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.

University Archive enters tapped.
When University Archive enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {U} or {R}.

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

{T}, Pay 1 life: Add {U} or {B}.
{1}, {T}, Sacrifice Unlit Alley: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

When Unmarked Vials enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
{1}, {T}: Add one mana of any color.

Add X mana in any combination of colors, where X is the amount of mana spent to cast Unravel Shattered Worlds.
Coalesce {7} (You may cast this from your graveyard for {7}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Vanishing 2 (This permanent enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
{T}: Add {C}.
When Unstable Footing is put into your graveyard from the battlefield, if it had no time counters on it, search your library for a basic land card, put it onto the battlefield, then shuffle.

When Unstable Orb enters, draw a card.
{3}, {T}, Sacrifice Unstable Orb: It deals 2 damage to target creature.

{T}: Add {C}.
{T}, Sacrifice Untethered Spire: Choose target land card in your graveyard that was put there from the battlefield this turn. Return that card to your hand.

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

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

Unzari Ruins enters tapped.
{T}: Add {C}.
Tap five untapped creatures you control: Unzari Ruins becomes a 10/10 Construct artifact creature with trample until end of turn. It's still a land.

({T}: Add {B} or {R}.)
Urban Wastelands enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Menace

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}.

({T}: Add {B} or {R}.)
As Vacated Bar enters, you may pay {1}. If you don't, Vacated Bar enters tapped.

When Vale Ruins enters, you gain 1 life.
{T}, Sacrifice Vale Ruins: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Valley Falls enters tapped unless you control two or more white and/or blue permanents.
{T}: Add {W} or {U}.

{T}, Pay 1 life: Add {W}.
{T}, Pay 1 life, Sacrifice Vast Savannah: Search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Hexproof
As long as an opponent controls a permanent you own, Vault Sentinel gets +4/+4.

As this permanent transforms into Velir, put four loyalty counters on it.
[+1]: Draw two cards, then discard two cards unless you discard a land card.
[–2]: Search your library for a multicolored card, reveal it, put it into your hand, then shuffle.
[–4]: Exile target permanent.

Venerated Beast can't be blocked by more than one creature.

{T}: Add {C}.
{T}, Pay 1 life: Add {R} or {G}.