Obelisk the Tormentor
Obelisk the Tormentor is shown as a level 12 monster when it is in fact a level 10 monster (although either level would require 3 tributes to summon it).
Kaiba states that Yugi wasn’t able to defeat his Blue-Eyes Ultimate Dragon. Although Yugi defeated one of the heads in their duel at Duelist Kingdom, he did not succeed in actually destroying the Dragon.
On his first turn, Kaiba actually played two monsters which is against the rules, even though Battle Ox was summoned while Dimensional Warrior was only set. When Kaiba summoned Obelisk the Tormentor, one of the monsters he tributed was the set Dimensional Warrior from the fist turn, however this monster should have destroyed by the Cyber Jar and was also referred to on at least one occasion as being a Trap Card.
Yami seems surprised to learn of his name and past from Ishizu, but he had already told Yugi that he was a Pharaoh and that his name was Yami in “The Wrath of Rebecca”.
Once again, Yami means ‘Dark’ in Japanese, but then most people refer Yami Yugi as pain Yami on the internet.
The three Blue-Eyes were NOT destroyed in the fire. Although it was never shown, none of the cards being used by the Robot Duelist were destroyed as Kaiba is seen using a number of them in later duels.
When Kaiba’s Battle Ox destroyed the face down card that was revealed as Cyber Jar when it’s Card effect activated it’s ATK/DEF was shown as 900/1000, but it is actually 900/900.