It was by such a fate as this that Muad’Dib met his own destiny. There was no opportunity to prevent this, no chance to save himself. The fall of a statue is an apt metaphor for the fall of a human spirit in his case. When we look at it, do we see a great mountain? Or perhaps a vast and chaotic chasm? Or a small, but solid, mass of stone?
He is an emperor like none who ever held power, a wise man to whom others are but a servant, a king of truth and a leader of power. He is not a warrior, but a wizard.
—’Muad’Dib: The God King of Arrakis’ by the Princess Irulan
It was once our Emperor Shaddam I was born. Shaddam I was a great warrior. He was a mighty ruler, a mighty warrior. His enemies could not stand against a warrior like Shaddam. And he had no enemy of the first rank. But his enemies were his friends.
Stars Without Number Revised also has options for Heroic Characters … as does the First Edition with Mandata Archive Stellar Heroes. Possibly combine the advantages there.
So those would be good to tweak if going the route of joining these two games.
There are a couple of d20 Superhero games like Deeds Not Words and Guardians, too.