What would happen if Superman was raised in Latveria by Doctor Doom since infancy (in Marvel)?
Kal-El crash landed in Latveria. He was discovered by Victor Von Doom. Instead of Superman or the Man of Steel, the Last Son of Krypton became the Man of Doom and the greatest hero in Latveria. Dr. Doom made modifications which made the Man of Doom immune to Kryptonite.
Superman would have been quite literally unstoppable and the greatest villain to exist in Marvel and DC. He would have eaten heroes for breakfast. Unaffected by magic since Doom would teach him how to use magic, he would have been the destroyer of worlds and the bringer of death & destruction. The four horsemen of the apocalypse rolled up in one.
Would Doom use his seldom used mind swap technique on Kal-El to make himself more of a threat? Or would someone close woo Kal-El away like Alicia Masters did with the Silver Surfer or Sue did with Namor?
Thoughts on how this would playout…
The “Man of Doom” vs Herald/King Thor…who would win?
If Kal-EL did turn out like that then he would indeed be unstoppable by the heroes in Marvel (except maybe somebody like Professor X, but even that is doubtful since Doom seems to be able to resist telepathic control) .
However, it is in no way given that Kal-El would turn out like that. It is also possible that he would turn against his 'father'.
Are character traits innate or educated? Big question...