For some reason Raja seems like the most natural pick to me. I can understand the motivations for Hahn, Gryz and Demi to help out at the end of the game, but I don't know why they would want to go to Rykros unless they just had nothing better to do. And Kyra had just left (no other reason, really... I don't really like Kyra, plot-wise).
Big tangent:
Thoul wrote:Or maybe even Seth, if he hadn't turned?
I don't know if there's a better topic for it, but I've always wonder if Seth actually "turned" at all. I've debated this one before on GameFAQs, and enjoyed the discussion. But there are sort of three possibilities with Seth.
1) He was Dark Force all along, and was consciously deceiving you.
2) He was a normal person who turned evil, and was consciously deceiving you.
3) He was a normal person sort of "possessed" by Dark Force, and was unconsciously deceiving you.
I always naturally thought of the third option because he never seemed outwardly evil, just with unusual strength and powers. And the way he seemed anguished when he transformed makes me think it was painful and he didn't, y'know, enjoy it.