Seto Kaiba Yugioh Everything Theory Expansion (The True AntiChrist of Yu-Gi-Oh)
So, this theory is an expansion of a theory made by the YouTuber YugiohEverything. He states Kaiba is the Yugioh equivalent if the Antichrist. I, however, see a different biblical relation when it comes to Kaiba. This theory will use his own as the basis for it. There are four points I will try to explain, and each one explains better of my own choice.
The first point is one YugiohEverything did not use. But as a part of a connection to YuGiOh canon, it does give credence to one of his facts. If you play Duel Links, Dark Side of Dimensions Kaiba has a phrase that is harder to place in the movie. Specifically saying, "The darkness...". It's taken out of context, but only one place matches its use. That is the moment Kaiba sees Aigami return in a grotesque shape and he can't go on. The look on his face also seems unlike any seen on Kaiba before, he looked melancholy and for the first time since he was "mind crushed" his eyes were glazed over. This will be important for the next point.
Point two is the ending of Dark Side of Dimensions. Everyone says Kaiba did the impossible and built a Time Machine, however, we can use another moment as an connection to that place. In GX, we see an alternate dimension where it is a literal desert. And it is considered to be connected to the Duel Spirit world because monsters are brought to life there. So, Kaiba could have been transported there. How, well point three exposes something no one notices for that series.
Kaiba seems to take a back seat after his final duel in the original series and even in DSOD. This isn't in Kaiba's nature. According to YugiohEverything Kaiba joined Darkness and became the Antichrist of YuGiOh. I believe, however, Kaiba made a deal with the only being he saw as powerful enough to get him what he wants. Darkness made a deal with Kaiba, and Kaiba would have given anything to duel the Pharaoh again. Darkness forced Kaiba to choose between his company and Yami. Kaiba ended DSOD by telling Mokuba he was in charge until he returned. And here's the final point.
How would he return without technology? If he was sent back in time, that's one thing that would not allow it. So, Kaiba had to use Darkness power to travel not through time, like he thought, but transferred his consciousness to the Duel Spirit world. At the rate of the elevator that Kaiba had made, it would need a precise point of re-entry that is not constant. Which makes sense with Mokuba's sense of danger at Seto's words, and Kaiba only using the elevator during certain times. That means Seto's body would be injured almost irreparably by the elevator. I say almost, because GX Kaiba still looks okay, although kept in shadow. I believe Kaiba is Darkness, and every action shown after DSOD is not Kaiba, but Darkness posing as Kaiba.
In the end, Kaiba might not be the Antichrist. But either a false prophet or even what could be considered the Beast as far as YuGiOh is showing. In fact, the true Antichrist of YuGiOh could very well be Z-Arc.
This makes more sense mainly due to his backstory and motives. As well as the fact that Z-Arc literally remade each Dimension except the one that was already taken over by Darkness' subordinate, Kaiba. GX failed because of Judai, 5ds failed thanks to Yusei, and Zexal failed thanks to Yuma. The standard dimension was a way for him to feel better about himself, rather than have to redo the rest without reward. Also, notice that each Dimension only holds the duelists from the previous series with unfinished stories. These are most likely to end up as his next targets for control.
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