Gozaburo was already rich when Kaiba gave him the boot. His strategies afterwards were effective, at the least, of continuing to churn a profit.
>subjegating his adopted father's real son
Before or after being turned into virtual stone?
>building a theme park
Michael Jackson built a theme park. Next.
>creating/ stealing hologram technology for a child's card game
I'll give him this. And he was his own guinea pig so I must give him due respect and credit for that.
>beating everyone except yugi, and main villains [at] a childs card game
Because children's card games are serious business.