oh man, lots to say.... so much that doesn't really need to be said though.
make him in the image of a messenger god, rather than a delivery boy.
Give him superspeed, or something. I would say wings, but we don't want too many characters with wings flying around. Maybe just add one thing. The summoning isn't that difficult to understand. I think it would be neat if he had a latent psychic power that hasn't completely manifested yet. So, we all know he can phase out with a five second warm up. Then, anyone can summon him, I would suggest just by will. There shouldn't need to be a pass-phrase or an object. If some one wants him, they have him kind of thing. He can't help but phase to them.
Have that flawed power and add one that's functional like superspeed, or psychic flight. Cause if he can phase shift, he should be able to fly. :)
Yah, I was talking about those two youngsters that your character is guarding. They seem to be an opening for other people to fit into your character's background
As far as I know, Xavier didn't always have a school running, first he aquired the x-men task force, and used storm, cyclops, and beast to train everyone in the danger room. I may be mistaken and brainwashed by the movies at this point. I just feel like we should start as adults and train the kids.
Original powers are so hard to think of. I've been trying to build one character for the LARGE group x-men game that E has, and it's taken me a whole week. I was almost finished twice, but my session kept timing out.