There are several continuities for Yu-Gi-Oh!, so I am forced to spend some time clarifying my classification of them. This question is asking for answers from the following four:
- The full manga series, starting from Yugi solving the puzzle and ending with the Ceremonial Duel and the Japanese version of the Dark Side of Dimensions movie.
- The Japanese Toei anime series, starting from Yugi solving the puzzle and ending with that movie about Red-Eyes Black Dragon.
- The Japanese non-Toei anime series, starting with the episode where Yugi summons Exodia against Kaiba and ending wherever the answerer finds convenient. I suspect that there will be no need to go further than Bonds Beyond Time. The only reason why I haven't stopped at the DM anime's Ceremonial Duel is because I suspect that some of GX may be relevant. As far as I know, the Japanese versions of Capsule Monsters and The Pyramid of Light can safely be excluded here. If they are relevant to your answer, try to also provide for those who exclude it.
- The English dubbed non-Toei anime series. This has the same start and end points as number #3, but 4Kids-original content such as Capsule Monsters and The Pyramid of Light may be included. It is not clear to me if the dubbed version of Dark Side of Dimensions belongs here. If that film is relevant to your answer, try to also provide for those who exclude it.
I am not particularly interested in hearing about any information from video games, merchandise, those feature duels where they bring in the voice actors, or anything else that isn't the above. I'm sure that they'll be interesting - Reshef of Destruction comes to mind - but I'm not interested in any answers that come solely from sources other than the above four. I also know of nothing to suggest that the other manga series, e.g. Yu-Gi-Oh! R and whatever the GX manga was called, would be of any relevance even if I included them. If you disagree with that, comment and I'll edit.
Now to get to my question: In each of these continuities, when, if ever, does Seto Kaiba start believing in magic? Furthermore, prior to the point in which he started believing, when did he last show disbelief?
I've deliberately left "magic" undefined. Answers are also free to give multiple points as their answer. For example, it is clear to me that manga Kaiba believed in magic by the end of Dark Side of Dimensions. You can't really argue that a guy who is
trying to break into the Egyptian afterlife
doesn't believe in magic. However, there are some clear suspicions earlier on. For example, during the final duel of Battle City, Kaiba starts to suspect that Yugi can see the future because Yugi was able to play Demon's Sanctuary without even looking at the card. In contrast, I can't recall the dubbed non-Toei anime Kaiba ever believing in any sort of magic.
