Whenever Undercover Butler attacks the player with the most life or tied for most life, it can't be blocked this turn.

You may have Undercover Operative enter the battlefield as a copy of any creature on the battlefield, except it enters with a shield counter on it if you control that creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

CARDNAME enters the battlefield with ten eyestalk counters on it.

If CARDNAME would be dealt damage, remove that many eyestalk counters from it instead. If you can't, sacrifice it.

Whenever CARDNAME attacks, reveal cards from the top of your library until you reveal an instant, sorcery, or enchantment card with converted mana cost less than the number of eyestalk counters on CARDNAME. You may cast it without paying its mana cost. Shuffle your library.

: Add .

, , Exile Underdark Rift: Roll a d10. Put target artifact, creature, or planeswalker into its owner's library just beneath the top X cards of that library, where X is the result. Activate only as a sorcery.

(: Add or .)

Underground Mortuary enters the battlefield tapped.

When Underground Mortuary enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

(: Add or .)

If damage would be dealt to Undergrowth Champion while it has a +1/+1 counter on it, prevent that damage and remove a +1/+1 counter from Undergrowth Champion.

Landfall — Whenever a land enters the battlefield under your control, put a +1/+1 counter on Undergrowth Champion.

Undergrowth Scavenger enters the battlefield with a number of +1/+1 counters on it equal to the number of creature cards in all graveyards.

Whenever an artifact enters the battlefield under your control, you may pay . If you do, each opponent loses 1 life and you gain 1 life.

, Sacrifice Underhanded Designs: Destroy target creature. Activate only if you control two or more artifacts.

Vigilance

When Undermountain Adventurer enters the battlefield, you take the initiative.

: Add . If you've completed a dungeon, add six instead.

Flash

Undersea Invader enters the battlefield tapped.

, , Discard a card: Return target creature card from your graveyard to your hand.

Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)

At the beginning of the end step, sacrifice Underworld Breach.

Underworld Charger can't block.

Escape—, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Underworld Charger escapes with two +1/+1 counters on it.

Enchant land

Enchanted land has ", Pay 1 life: Draw a card."

Underworld Fires deals 1 damage to each creature and each planeswalker. If a permanent dealt damage this way would die this turn, exile it instead.

Underworld Rage-Hound attacks each combat if able.

Escape—, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Underworld Rage-Hound escapes with a +1/+1 counter on it.

: Add one mana of any color. During your next untap step, as you untap your permanents, return Undiscovered Paradise to its owner's hand.

When Undying Beast dies, put it on top of its owner's library.

Exile cards from the top of your library until you exile a nonland card. Undying Flames deals damage to any target equal to that card's mana value.

Epic (For the rest of the game, you can't cast spells. At the beginning of each of your upkeeps, copy this spell except for its epic ability. You may choose a new target for the copy.)

Enchant creature

Enchanted creature gets +2/+2 and can't block.

When Undying Rage is put into a graveyard from the battlefield, return Undying Rage to its owner's hand.

Target nontoken creature you control gets +2/+0 and gains double team until end of turn. It also gains first strike until end of turn if it has the same name as another creature you control or a creature card in your graveyard.

Put a +1/+1 counter and a lifelink counter on target creature.

As an additional cost to cast this spell, discard a card.

Draw two cards and create two Treasure tokens. (They're artifacts with ", Sacrifice this artifact: Add one mana of any color.")

For each player, exile up to one target nonland permanent that player controls. For each permanent exiled this way, its controller cloaks the top card of their library. (To cloak a card, put it onto the battlefield face down as a 2/2 creature with ward . Turn it face up any time for its mana cost if it's a creature card.)

Draw three cards.

Adamant — If at least three blue mana was spent to cast this spell, scry 3.

Spree (Choose one or more additional costs.)

+ — Destroy target creature.

+ — Create a 1/1 red Mercenary creature token with ": Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."

, Pay 1 life: Draw a card, then discard a card.

Unhallowed Cathar can't block.

Unhallowed Phalanx enters the battlefield tapped.

Black legendary creatures you control have "bands with other legendary creatures." (Any legendary creatures can attack in a band as long as at least one has "bands with other legendary creatures." Bands are blocked as a group. If at least two legendary creatures you control, one of which has "bands with other legendary creatures," are blocking or being blocked by the same creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Enchant creature

When enchanted creature dies, return that card to the battlefield under your control with a +1/+1 counter on it.

Exile target attacking creature if its power is less than or equal to the number of Soldiers on the battlefield.

Unimpeded Trespasser can't be blocked.

Draw a card, then you gain life equal to the number of cards in your hand.

Destroy target creature. If you control an artifact, Unlicensed Disintegration deals 3 damage to that creature's controller.

Target creature gets +2/+0 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Search your library for a nonlegendary card, put that card into your graveyard, then shuffle.

Devoid (This card has no color.)

Target creature gets +2/+0 until end of turn. Regenerate it.

Target creature gains haste until end of turn.

Enchant creature

When Unquestioned Authority enters the battlefield, draw a card.

Enchanted creature has protection from creatures.

Changeling (This card is every creature type.)

Whenever you or a permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays .

2 — : Switch this creature's power and toughness until end of turn.

4 — Whenever this creature attacks, it gets +5/+5 until end of turn.

2 — 3/2

3 — 2/7

Enchant creature

Enchanted creature gets +2/+1 and has menace. (It can't be blocked except by two or more creatures.)

Target creature gets +X/+X until end of turn.

Search your library for a basic land card, put that card onto the battlefield, then shuffle.

Menace (This creature can't be blocked except by two or more creatures.)

, Exile Unwilling Ingredient from your graveyard: You draw a card and you lose 1 life.

Untap all artifacts you control during each other player's untap step.

Disguise (You may cast this card face down for as a 2/2 creature with ward . Turn it face up any time for its disguise cost.)

When Unyielding Gatekeeper is turned face up, exile another target nonland permanent. If you controlled it, return it to the battlefield tapped. Otherwise, its controller creates a 2/2 white and blue Detective creature token.

Target creature gains flying until end of turn.

Draw a card at the beginning of the next turn's upkeep.