Charles could be Absolon Mercator, Mr M, one of the 15 omega level mutants that is missing.
A bald man, I may be seeing things but I think the hand gestures of Charles kinda look like Mr M's.
He only appeared in 3 books over a decade ago. District X, Mutopia (the district X House of M tie in), and XMen the 198 after House of M.
Something unusual about him, is he got his first mention in a decade a few months after this book. In Rosenberg's Astonishing XMen when the bad guys capture Miss Sinister, someone says, be careful, we don't want another Mister M incident.
Mutopia had a plot about a huge mutant tree that gave fruit