The following individual card rulings have been compiled from the archived UDE Gameplay FAQ database [REF] and the Konami Card Rulings documents [CRMS, RGBT, ANPR, SOVR, ABPF, HA01, SDMM]. Notable cards have streamlined rulings and additional information cross-referenced against Pojo / Duelistgroundz.
ULTIMATE ANCIENT GEAR GOLEM
(C) This monster cannot be Special Summoned except by Fusion Summon. (1) During battle between this attacking card and a Defense Position monster whose DEF is lower than the ATK of this card, inflict the difference as Battle Damage to your opponent. (2) If this card attacks, your opponent cannot activate Spell or Trap Cards until the end of the Damage Step. (3) If this card is destroyed, you can Special Summon 1 "Ancient Gear Golem" from your Graveyard, ignoring the Summoning conditions.
ULTIMATE BASEBALL KID
ULTIMATE INSECT LV1
ULTIMATE INSECT LV3
ULTIMATE INSECT LV5
ULTIMATE INSECT LV7
ULTIMATE OBEDIENT FIEND
If you control "Ultimate Obedient Fiend" and have no hand and no other monsters, but you have Spell or Trap Cards on the field, "Ultimate Obedient Fiend" cannot attack.
(1) You can pay 500 Life Points to Normal Summon or Set 1 extra monster. You can only activate this effect during your Main Phase or your opponent's Battle Phase.
ULTRA EVOLUTION PILL
(1) This card can attack your opponent directly. (2) When this card successfully attacks directly, if you control a "Frog" monster other than "Frog the Jam" or "Unifrog", you can destroy 1 Spell or Trap your opponent controls.
UNLEASH YOUR POWER!
Activate only during the Battle Phase. Synchro Summon 1 Synchro Monster. (Send the appropriate Synchro Material Monsters to the Graveyard.)
URIA, LORD OF SEARING FLAMES
(C) This card cannot be Normal Summoned or Set. (S) This card cannot be Special Summoned except by sending 3 face-up Trap Cards you control to the Graveyard. (1) This card gains 1000 ATK for each Continuous Trap Card in your Graveyard. (2) Once per turn, you can destroy 1 Set Spell or Trap Card your opponent controls. (2C) Spell and Trap Cards cannot be activated in response to this effect's activation.
VALHALLA, HALL OF THE FALLEN
VALKYRION THE MAGNA WARRIOR
VAN'DALGYON THE DARK DRAGON LORD
(1) After a Counter Trap Card you control negates the activation of an opponent's card(s) or effect(s), you can Special Summon this card from your hand. (2) Then activate the appropriate effects, based on the type of cards negated:
• Spell: Inflict 1500 damage to your opponent.
• Trap: Select and destroy 1 card your opponent controls.
• Effect Monster: Select 1 monster in your Graveyard and Special Summon it.
VANGUARD OF THE DRAGON
(C) This card cannot be Special Summoned. (1) While this card is on the field, neither player can Special Summon monsters.
VARIETY COMES OUT
VEHICROID CONNECTION ZONE
VEIL OF DARKNESS
VENNOMINAGA THE DEITY OF POISONOUS SNAKES
VENNOMINON THE KING OF POISONOUS SNAKES
(1) When a face-up Insect-Type monster is destroyed and sent to the Graveyard, its controller can add 1 Insect-Type monster with the same Level as the destroyed monster from their Deck to their hand.
VERSAGO THE DESTROYER
(1) You can substitute this card for any 1 Fusion-Material Monster. When you do this, the other Fusion-Material Monster(s) must be the correct one(s).
(1) Once per turn, you can select and Special Summon 1 Dragon-Type monster in your opponent's Graveyard to your side of the field. (2) Your opponent cannot select another face-up Fairy-Type monster as an attack target.
VICTORY VIPER XX03
(1) When you take Battle Damage while this card is in your Graveyard, remove it from play. Then, if there is a FIRE monster other than "Volcanic Counter" in your Graveyard, inflict damage to your opponent equal to the amount of Battle Damage you took.
(1) When this card is sent to the Graveyard, inflict 500 damage to your opponent. (2) If this card is sent to the Graveyard for the effect of a "Blaze Accelerator" card, you can send 2 "Volcanic Scattershots" from your hand / Deck to the Graveyard to destroy all monsters your opponent controls.
(1) Once per turn, while this card is in the Graveyard, you can pay 500 Life Points to add 1 “Volcanic Shell” from your Deck to your hand.
VOLTANIS THE ADJUDICATOR
VWXYZ-DRAGON CATAPULT CANNON
(1) Once per turn, you can equip this card to a "V-Tiger Jet" you control, OR unequip it to Special Summon this card in face-up Attack Position. (2) When equipped to a monster by this card's effect, the equipped monster gains 400 ATK and DEF. (C) (A monster can only be equipped with 1 Union Monster at a time. If the equipped monster would be destroyed by battle, destroy this card instead.)
WALL OF ILLUSION
WALL OF IVY
WALL OF REVEALING LIGHT
(1) During your Main Phase, you can send this card to the Graveyard to inflict 1000 damage to your opponent for each of your Standby Phases that have passed since this card was activated.
WHITE MAGICIAN PIKERU
WHITE NIGHT DRAGON
(1) Negate the activation of any Spell or Trap Card that targets this card, and destroy that card. (2) When a face-up monster you control is selected as an attack target, you can send 1 Spell or Trap Card you control to the Graveyard to change the target to this card.
WICKED-BREAKING FLAMBERGE - BAOU
WILD NATURE'S RELEASE
WINGED KURIBOH LV10
WITCH DOCTOR OF SPARTA
WITCH OF THE BLACK FOREST
WITCH OF THE BLACK ROSE
WOLF IN SHEEP’S CLOTHING
WRATH OF NEOS
WYNN THE WIND CHARMER
XING ZHEN HU
(1) When this card inflicts Battle Damage to your opponent while they have 4 or more cards in their hand, place 1 random card from their hand on top of their Deck.
(C) This card cannot be Normal Summoned or Set. This card cannot be Special Summoned except while you control 2 or more face-up "X-Saber" monsters. (1) Once per turn, you can Special Summon 1 Level 4 or lower "X-Saber" monster from your Graveyard.
(1) Once, while this card is face-up on the field; you can negate the attack of 1 of your opponent’s monsters. (2) If this card destroys a Defense Position monster your opponent controls by battle, you can Special Summon 1 Level 4 or lower “X-Saber” monster from your Graveyard.
1 Tuner + 1 or more EARTH monsters
(1) You can Tribute 1 "X-Saber" monster to discard 1 random card from your opponent's hand.
XYZ FUSION MONSTERS
The following rules apply to "XYZ-Dragon Cannon", "YZ-Tank Dragon", "XY-Dragon Cannon", and "XZ-Tank Cannon".
(1) Once per turn, during your Main Phase, you can equip this card to "X-Head Cannon" you control as an Equip Card, OR unequip it to Special Summon this card in face-up Attack Position. (2) While equipped to a monster by this effect, that monster gains 400 ATK and DEF. (C) (A monster can only be equipped with 1 Union Monster at a time. If the equipped monster would be destroyed by battle, destroy this card instead.)
YELLOW BABOON, ARCHER OF THE FOREST
(1) When a Beast-Type monster you control is destroyed by battle and sent to the Graveyard, you can remove from play 2 Beast-Type monsters in your Graveyard to Special Summon this card from your hand.
YUBEL - TERROR INCARNATE
YUBEL - THE ULTIMATE NIGHTMARE
ZABORG THE THUNDER MONARCH
ZEMAN THE APE KING
ZERADIAS, HERALD OF HEAVEN
(1) Once per turn, during your Main Phase, you can equip this card to "X-Head Cannon" or "Y-Dragon Head" you control as an Equip Card, OR unequip it to Special Summon this card in face-up Attack Position. (2) While equipped to a monster by this effect, that monster gains 600 ATK and DEF. (C) (A monster can only be equipped with 1 Union Monster at a time. If the equipped monster would be destroyed by battle, destroy this card instead.)
(1) Once per turn, you can send 1 Monster Card from your hand to the Graveyard to Special Summon 1 Level 4 or lower Zombie-Type Monster from either player's Graveyard.
(1) Once per turn, during your Main Phase, if you control this card on the field, you can equip it to your "Decayed Commander" as an Equip Card, OR unequip the Union equipment and Special Summon this card in face-up Attack Position. (2) While equipped to a monster by this card's effect, increase the ATK/DEF of the equipped monster by 500 points, and each time it destroys 1 of your opponent's monsters, your opponent discards 1 card randomly from his/her hand. (C) (1 monster can only be equipped with 1 Union Monster at a time. If the equipped monster is destroyed as a result of battle, destroy this card instead.)
(1) All monsters on the field and in any Graveyard become Zombie-Type monsters. (2) Neither player can Tribute Summon monsters, except Zombie-Type monsters.
ZOMBYRA THE DARK