User blog comment:20thCentFopp/Submariner vs. Doctor Doom: What Makes A Supervillain?/@comment-6731922-20131220035709/@comment-23748647-20131220042914

I think he was originally set up as the arch enemy, but when he got his sympathetic back story, some o his edge was lost. Goblin makes more sense now a days. But in the Silver Age, totally Otto.