...Or he could just be a badass. He's pretty much a dark palette swap of Cloud, anyway.
Rchi-chan not knowing or noticing could be explained by her young age (maybe he left a few hundred years ago; she's only 100) and his being more powerful than her. They also rarely if ever bring up his name in-series, and it could be that, if Rchi-chan knew it, she'd suddenly realize he was a demon who'd left a long time ago.
- Jossed. He's the hero Creasion...though Ros AND Creasion are fake names.
I certainly hope so, but it is a comedy series after all, so perhaps not.Though, even if he does, he probubly still wont get any respect.
- Confirmed. In the manga, at least.