The Demon Lord Doesn't Want to be a Super Hero
When the demon lord of a fantasy world is about to lose at the hands of the five chosen heroes of light, he instead flees into an interdimensional portal.
He ends up on a near-future Earth where an alien race has begun sending periodic invasion strikes against one city at a time. To "help" humanity (or perhaps as part of some sort of test) other (or perhaps the same) aliens unleashed a mutagenic virus on humanity that has transformed a small percent into superhumans. While these new super heroes have proven invaluable in fighting off the alien attacks, the havoc caused by the new super villains has only added to the chaos, and human society teeters on the brink of collapse.
Will the addition of one demon lord, determined to rule over humanity, be the final straw, or will he end up becoming the super hero, despite himself, that humanity needs in order to surivive?