Sean Cassidy / BansheeA detective and minor Irish nobleman, Sean Cassidy was a former Interpol inspector with flight and sound manipulation abilities. After his wife died in a terrorist bombing, he blamed his cousin, causing him to run off with his daughter and driving a rift between the two. He was mind-controlled by an alien terrorist group but freed by the X-Men. Later, he joins the X-Men when the original five are kidnapped. Being about 10-15 years older than the rest of the recruits, he was only active for a short amount of time but still hung around as a reserve and as a mentor, who applied his experience in espionage and anti-terrorism to the younger members of the group.
Funetik Aksent: She slips into a Kentucky accent when scared or stressed.
I Just Want to Be Special: Husk was revealed as this. Her brother was already the super-hero Cannonball, and she tried everything she could to get mutant powers to develop, almost killing herself a few times. Finally she just about gave up, crying and clenching herself... when her skin started flaking off like old wallpaper. She ripped and shredded and tore herself up, which for anyone else would have been scary as hell, but for her, it was the happiest moment of her life.
Magic Pants: Husk has the ability to transform her skin into any material she can think of; but she must tear off the existing layer to do so. This results in her being naked a fair amount of time, but censor steam is not used in all scenes if her new skin serves the purpose of costume. She has specifically refused to revert to her human form on occasions because of her nudity.
May-December Romance: For a while, she was in a relationship with Archangel. This has since fallen by the wayside.
Art Evolution / Progressively Prettier: Skin became increasingly attractive over the course of the book's run, going from downright ugly in his first appearances to basically becoming a grey-skinned Gambit with a goatee.
Blessed with Suck: He's got extra skin. Like, a lot. Like six feet of it. He keeps it all in normally, and it really just amounts to a limited ability to stretch, but it's still just really weird.
Super Power Lottery: Monet St. Croix had flight, superstrength, superspeed, nigh-invulnerability, telepathy, telescopic vision and genius-level intellect. Autism too, but it was treated as a superpower more often than not. She could also merge with her siblings (or her siblings could merge to form her), and the siblings had powers of their own.
Blessed with Suck: Chamber's mutation gave him the ability to emit fire from his mouth and chest area. His inability to turn it off eventually completely destroyed his lower jaw and most of his chest. He didn't really feel any pain from it, but he's still missing his jaw and has a nearly completely exposed ribcage.
Power Degeneration: He had an explosive power that blew off his jaw and upper chest prior to joining the team. Using his power slowly widened the explosive area, he near literally had part of his face and chest "on fire.
Legacy Character: The Penance body has had several inhabitants. In her original Mysterious PastWild Child form, she was revealed to be the true Monet St. Croix. She was freed only by her sisters (see below) taking up residence. When they were freed, the body was thought to be empty... yet eventually began to act on its own, but later scratched the word "home" to show that whoever she is now, she still sees Gen X as her friends. This is the current Penance, and there is little attempt to answer the "did the body become sentient on its own, or is yet someone else stuck in there, and if so, who?" question.
Touch of Death: Not to Rogue's level, let alone Wither's, but she's every bit as razor-sharp as she looks, and the material she's made of is also rather dense, said to be diamond-hard. Though nobody would ever come out and say she's Wolverine-level in this respect, she is the go-to person for slashing apart the otherwise-undamageable bad thing and has had some impressive feats. This makes touching anyone without gravely harming them quite difficult.
Demoted to Extra: The only members of the St. Croix clan to not return after Generation X ended, despite having been who we thought of as Monet for quite some time.
Fusion Dance: Emplate + The M-Twins = M-Plate. Also, the Penance reveal is that that is the true Monet, while the twins merged to become a facsimile of their sister.
Heroic Sacrifice: To free the true Monet from the Penance body, they had to take up residence in it themselves.
Polar Opposite Twins: Nicole's your normal talkative 8-year old, but Claudette suffers from what is referred to as autism but presents more as "perpetually staring in a given direction, but insanely powerful on the rare occasion that she acts."
Tangled Family Tree: Worse when part of your powers is merging with any family member to become a whole new person who isn't the sum of your parts.
Power Limiter: Psychic blocks keep him from being as all-powerful as his full potential. Whatever his power set at any given time is what leaks through. Naturally, using his full power tends to make any of it unusable for some time. These days, he has no powers and feels like the odd one out with the Fantastic Four as his family and a beyond-Reed-class genius as his little sister.
Ensemble Darkhorse: It's Morph from X-Men (the animated series) all over again. Introduced to be a Sacrificial Lamb, she was loved so much that she was brought back: first in Age of Apocalypse, whose Blink gets to survive the Snap Back and become the leader and main character of Exiles. With that series currently not in production, the original Blink has returned.
Portal Cut: Her power was to "blink" things to shreds in a way that only works in a comic book... thankfully.
Progressively Prettier: In a roundabout way. In the Phalanx Covenant X-Over that leads to the creation of Generation X, her colors were a bit dingier and her haircut... interesting. Then we meet the cute AOA Blink. When that version moves to Exiles, she basically becomes a pink supermodel with only the facial markings to remind you of Gen-X Blink. When Gen-X Blink returns in Regenesis, she is Exiles Blink with short hair in terms of both design and powers.
Teleporters and Transporters: It turns out this is her true power; in its unrefined state, it's bad news - imagine if, from your waist and above, every molecule in your body was transported a fraction of a centimeter to the left. But Exiles Blink can create portals to any place she can think of, and with external help, even cross dimensions. Gen-X Blink can now use her powers in this way since her return.
Japheth / MaggottA south African teenager from a poor family. As a child, his family thought he was dying from stomach cancer because his abdomen constantly bulged and he was constantly hungry. Actually, he was going through a mutation in which his stomach turned into a pair of semi-autonomous slugs. To feed, Japheth had to have the slugs burst out of his stomach, feed on any substance, then return, giving him a burst of superstrength. Japheth joined the X-Men for only a short time before vanishing and reappearing years later to be killed in a Canadian concentration camp for mutants.
Older Alter Ego: Originally Maggott is just a skinny teenager with normal skin complexion but when he powers up by his digestive matter-eating slugs, his skin turns blue and becomes musclebound to fight.
Blessed with Suck: While powerful, if he didn't feed on enough marrow, he'd eventually be drawn back into an Eldritch Location where he would be horribly tortured by the creatures therein. Despite this, he seemed to have fun being evil.
Psychic Powers: Adrienne has psychometry in which she can read "psychic imprints" that people leave on objects that they have handled and sometimes can even look into the future of the person or object she touches.
I'm a Humanitarian: While he doesn't eat people (that we know of), he's not adverse to stuffing and mounting them as trophies, and his prize possession is the skull of a child he personally shot between the eyes.
Rape as Drama: If the creepy grin he gave when he mentioned he was considering leaving the female Gen Xers alive is any indication...
Scare 'Em Straight: It's noted in the issues that he was given a blank check to do what he pleased to America's teenagers in order to prevent another Columbine, but this is probably no longer the case due to the sliding timescale and it's implied in the final issue of the arc that he doesn't really care about doing that anyway and took the job so he could torture and kill lots of kids.
Twofer Token Minority: The Cheif is a half-Huguenot, half-Ojibwe mutant. His unseen wife is a woman who's half-Armanian and half-Jewish. Which makes Tracy a quarter Huguenot, Ojibwe, Armanian, Jewish female, but she's not a mutant.
Badass Normal: Standing up to his grandfather, Hunter Brawn, having him arrested for ordering the death of Mr. and Mrs. Lee, Jubilee's parents.