7. Rachel Grey-Summers
Rachel Grey-Summers is the daughter of Cyclops and Jean Grey from the alternate timeline in the "Days of Future Past" storyline. She was forced to become a mutant "hound" and track other mutants before escaping to the standard Marvel timeline. Grey-Summers has incredibly potent telekinetic and telepathic powers, as well as certain time-manipulation powers and she currently teaches at the Jean Grey School in the comic books. Rachel has also served as a host to the cosmic entity known as the Phoenix Force. Whilst bonded to it, she demonstrated heightened telekinetic and telepathic powers, the ability to manipulate energy and life-forces and limited cosmic awareness - her power in this state was such that she was even able to defeat Galactus. She would look great on film and it's about time she got that chance. It's a crime to have so many X-Men movies without her appearing!