Maybe the reason why Seto is so opposed to the idea of destiny and fate is because he is terrified of anyone and anything infringing upon the autonomy he worked so hard to create for himself
Because of Gozaburo’s abuse he saw the darker sides of paternalism, so the idea of an all powerful force like destiny and fate deciding his path for him “for his own good” reminds him too much of that powerlessness.
I'll forever be fascinated with the idea of what Seto would have become if he'd never gotten control of KaibaCorp. What Gozaburo would have turned him into. How much worse he would have gotten without an outlet for the pent up everything negative in his heart.
What Mokuba would have become, once Gozaburo decided to take an interest in his education. How the brothers' relationship might never recover because Mokuba blames his brother for all of this.
What paramilitary training they might have eventually gotten. What crimes Kaiba would probably go on to commit.
How Seto probably would have snapped one day and finally murdered his stepfather to take control.
This might be kinda niche but does anyone remember how Kaiba was straight up being blamed for what happened to Gozoboro??? Like he literally had someone run up to him and start yelling saying he, a child, killed Gozoboro… like that’s so insane to me
Next part of my "Yu-Gi-Oh as a American cartoon of the early 2000s" project, this time with Kaiba's family! (part one here)
I imagine Seto wouldn't have a personality all that different from the YGO dub, but would fit more into a "rich bully from school" role, while Mokuba is more similar to the early manga/season 0 as a little spoiled kid, but they both become nicer over time.
Gozaburo and Noah are the ones i imagine being more different: for starters, Gozaburo's still alive! I can't imagine them just allowing Seto and Mokuba to live alone, so he would still be around being a very unpleasant person, and even worse parent (not sure if he would still have adopted them or if his their biological parent here). Noah would be 100% AI here, created by Gozaburo to replace Seto as his successor after he starts disobeying him.
I was thinking about how in DSOD Shadi rescused the Plana kids from terrible situations, with Aigami and Sera being rescued from abuse, and a thought struck me--what if he rescued the Kaiba brothers in the same manner and gave them the Plana powers?
That could be a really interesting AU to have Kaiba grow up around magic, and his mind is definitely sharp enough to both comprehend and counter it, as the movie shows. I could see him being tempted to take revenge on Gozaburo the same was Aigami was for Ryou, or rallying the kids together after Shadi's death to continue focus on their utopia.