Nerfing/Buffing Yu-Gi-Oh! Video Game Promos

[Baneful]

Dark Duel Stories

Seiyaryu - LV6 with 1300 DEF instead of LV7 with 2300 DEF

Acid Trap Hole - The monster is removed from play when it's sent to the graveyard.

Salamandra - Equip target cannot be targeted by opponent's card effects.

Eternal Duelist Soul

Graceful Dice - ATK increases by 300x the die roll (instead of 100)

Skull Dice - ATK decreases by 300x the die roll (instead of 100)

Forbidden Memories

Harpie's Pet Dragon - Can be summoned without tributes if you control a Harpie Lady.

Duelist of the Roses

Alpha the Magnet Warrior - When normal summoned, you can Special Summon 1 "TMW" monster from your deck.

Beta the Magnet Warrior - When normal summoned, you can Special Summon 1 "TMW" monster from your graveyard.

Gamma the Magnet Warrior - When normal summoned, you can add 1 "TMW" monster to your hand.

Stairway to the Destined Duel 

Valkyrion the Magna Warrior - Is a Fusion Monster which can be summoned via "contact fusion"

Harpie's Feather Duster - Can only activate if you control a "Harpie" monster.

Sinister Serpent - Cannot activate it's effect if you activate it during the previous turn.

The Sacred Cards

Riryoku - Also add the lost ATK to your life points and subtract it from your opponent's.

Negate Attack - 2nd Effect: Can be used during your Battle Phase to negate the effect of a Trap Card

Falsebound Kingdom

Goblin Fan - Effect becomes "The effects of your opponent's LV3 or lower monsters are negated"

Dawn of Destiny

Dark Sage - No summoning restrictions (Summoning via Time Wizard is optional)

Yugi the Destiny

Thousand Knives - Can activate with any Spellcaster-type monster.

Kaiba the Revenge

Aqua Chorus - Stat boost is 1500 - not 500.

Seal of the Ancients - No LP payment.  Can also view the opponent's hand too.

Joey the Passion

Sebek's Blessing - Gain double the damage - not equal

Sword of Dragon's Soul - Dragon-type monster is banished immediately (instead of destroyed later).

Reshef of Destruction

Dark Magician Knight - No summoning restrictions (Using Knight's Title is optional)

Knight's Title - Can tribute any monster for the effect.

Sage's Stone - Can summon DM from the graveyard as well.

Capsule Monster Coliseum

Teva - Stat changes from "LV5/2000/1500" to "LV4/1800/500".  Effect works on a regular Normal Summon.

Inferno Hammer - Stat changes from "LV6/2400/0" to "LV4/1850/0".

World Championship 2004

Fairy King Truesdale - ATK boost becomes 300 (but not Defense Position restriction)

World Championship 2005

Silent Swordsman LV7 - No summoning restrictions.

Destiny Board Traveler

D.D. Assailant - Stats are changed from "LV4/1700/1600" to "LV4/1600/1400"

Emes the Infinity - Stats are changed from "LV7/2500/2000" to "LV6/2500/0"

Twin-Headed Beast - Stats are changed from "LV5/1900/1700" to "LV4/1900/700".  It cannot attack directly.

Nightmare Troubadour

Silent Magician LV4 - Base ATK of 1500.  Only needs 3 Spell Counters to Summon SMLV8 and you can do it immediately instead of waiting.

Silent Magician LV8 - No summoning restrictions.

GX Duel Academy

Elemental HERO Necroshade - Is LV4 instead of LV5

Hero Ring - Also, target cannot be destroyed by card effects.

World Championship 2006

Golden Homunculus - Base ATK of 2000 instead of 1500.  Gains 400 ATK per card instead of 300.

Helios The Primordial Sun - When it is Summoned, you can banish up to 3 cards from your opponent's graveyard.

Helios Duo Megistus - Revival effect also works if its destroyed by a card effect.

GX Tag Force

Phantom Beast Cross-Wing - Has 1800 base ATK.  Stat boost (in grave) is 500 - not 300.

Phantom_Beast_Wild-Horn - When it inflicts battle damage, add 1 "Phantom Beast" monster from your deck to your hand.

Phantom_Beast_Thunder-Pegasus - Makes the opponent's monster's ATK 0 (instead of just the battle damage)

GX Spirit Caller

Brain Crusher - LV6 instead of LV7

Hunter Owl - When it's destroyed, Special Summon 1 LV4 or lower WIND monster from your deck.

Masked Chopper - After the damage is inflicted, draw 2 cards.

World Championship 2007

Spell Striker - When it inflicts battle damage, add 1 "Spell Striker" from your deck to your hand.

Exploder Dragon - Effect becomes "When this card is destroyed, destroy 1 monster on the field.  You take no battle damage in battles involving this monster"

GX Tag Force 2

Mad Reloader - Works if destroyed via card effect, as well.  You only need to discard 1 card instead of 2.

Chaos Burst - Instead of tributing, you send a monster from the deck to the graveyard.

World Championship 2008

Deep Diver - Effect becomes "When this card is destroyed in battle, pay half of your life points to add 1 card from your deck to your hand".