5 Mutants That Have Never Been X-Men (But Should Sign Up)

Jamie Madrox aka The Multiple Man has been a good guy for many years investigating and solving mutant related issues as a member of X-Factor. Contrary to what Ultimate X-Men and the film X3: X-Men United show, Madrox is not and hasn't been a member of the Brotherhood of (evil) mutants. Madrox has the mutant ability to copy himself and split into many versions each able to recombine and bring with them any attained knowledge whilst they were separate. I sometimes can't believe that Madrox hasn't been a member of the X-Men (and i'm happy to be corrected here). I'm sure he was a member of the X-Corporation but I don't count that as being an X-Man. Madrox has worked alongside the X-Men on (ahem) multiple occasions however, the most recent being during the Messiah Complex story where he went to the future and was branded with an 'M' alongside Layla Miller. He did this at the behest of then leader of all of the X-teams, Cyclops. Madrox if he were to join a team would want to talk to Cyclops about the means he would be using to accomplish his goals. Part of me thinks that Madrox's personality is better suited to working at Wolverine's school as he generally isn't a dark character, has a sense of humour and his power set could be used for some funny moments, such as teaching more than one class at a time, spying on the teaching staff and so forth. I also feel that making it as a X-Man is one of the greatest honours a mutant could strive for and there is a level of mainstream acceptance from the real world fans and the in-world characters such the Avengers, that becoming an X-Man shows that you are a hero willing to fight for a safer world (although maybe not so much in recent times). With X-Factor finishing up, it will be interesting to see where the Multiple Man chooses to go next - unless he decides to work with multiple teams?