msem-instigator

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

Haste
When Urud Stingswoop enters the battlefield, it gains flying until end of turn.

Assault {1}{R} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Urudi Warlord assaults, it gains first strike until end of turn.

You may have Urushi, the Ripple in the Smoke enter the battlefield as a copy of any creature on the battlefield, except it's an enchantment. (It's not a creature.)

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 the battlefield, create an Idol token.
As long as you're in a renaissance, artifacts you control have “{T}: Draw a card.”

Flash
Death knell — Put a +1/+1 counter on each creature you control. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

Foretell {B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Destroy target creature or planeswalker. You lose 4 life unless this spell was foretold.

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.)

Foretell {X}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Gain control of target creature with power 2 or less. If this spell was foretold, gain control of target creature with power X or less instead.

First strike (This creature deals combat damage before creatures without first strike.)

Exile all lands. For each land card exiled this way, Uttermost Obliteration deals 1 damage to that land's controller.

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.

Whenever V-4 Fixit or another artifact enters the battlefield under your control, target creature you control gets +1/+1 until end of turn.

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

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
When Vaeldan's Liberator dies, you may exile it. If you do, return a permanent card with mana value less than or equal to Vaeldan's Liberator's power from your graveyard to your hand.

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.

As Vaertris' Master Plan enters the battlefield, exile the top five cards of any player's library.
You may play cards exiled with Vaertris' Master Plan.
When there are no cards exiled with Vaertris' Master Plan, return it to its owner's hand.

[+1]: Until end of turn, whenever target creature deals combat damage to a player, that player mills two cards.
[–1]: Tap target creature. It can't become untapped for as long as you control Vaertris, Mindmelder.
[–6]: You get an emblem with “Whenever you draw a card, target player mills three cards” and “{2}{U}: Draw a card.”

When Vagabones enters the battlefield, look at the top two cards of your library. Put any number of them into your graveyard and the rest on top of your library in any order.

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

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

Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Vigilance
Engage (This creature must be blocked each combat if able.)
Other Soldiers you control get +1/+1 and have first strike.

Valeron Vanguard can't be blocked by 1/1 creatures.

[+1]: Reveal the top card of your library. If it doesn't have the same name as a card in your graveyard or a permanent you control, put it into your hand. Otherwise, put it into your graveyard.
[–2]: Return target card from your graveyard to your hand.
[–8]: Return all other cards from your graveyard to your hand. Until end of turn, spells you cast cost {5} less to cast.