Who Is Superboy Prime

Is Superboy-Prime stronger than Superman-Prime?

Superboy Prime is more powerful than Superman, and Power Girl is more powerful than Supergirl. Krypton was a distant planet orbiting a rare red sun.

How did Superboy-Prime become evil?

In the aftermath of Crisis on Infinite Earths when Earth-Prime was destroyed, Superboy-Prime spent time in a paradise dimension where he grew bitter and sinister.