"Inspired tinkerer"- from the back of Excalibur #2
Katherine Pryde, affectionately called "Kitty" by friends and family, joined the X-Men way back when at the age of 13. At the time she was a wide-eyed kid who spouted terms like "Golly" and "keen" left and right, and yet she was one of the smartest members to join the team so far- right up there with Professor X and Cyclops at times.
Her phasing power was at the time unique, and remains so even today- few other characters have any power like this one. They're mostly all really strong or telepathic or something. It was interesting because in addition to letting her pass through solid matter as if she were a ghost, it also disrupted electrical systems. She ruined many a computer before she learned to control her powers.
The most entertaining part of Kitty's stay with the X-Men was her progression of costumes and codenames. She began as Sprite, in a traditional "X-Man-in-training" uniform, and then designed her own INCREDIBLY tacky costume. After that she just sort of went wild, changing her name first to Ariel and then finally to Shadowcat, and going through a progression of upwardly evolving costumes until she finally settled on the nice blue one above.
Shadowcat proved herself time and again to be a valuable member of the team, despite her age (she only aged about two years during the eight years she was in the title). It wasn't until the Mutant Massacre, when she was mortally injured, that she had to be taken out of the team. Her phasing power was turned against her, and she was steadily losing the ability to stay the least bit cohesive. Soon she would simply fade out of existence. The help to her situation came from the Fantastic Four and, ironically, Dr. Doom. Through them the process was reversed, and she slowly but surely began to regain the ability to stay solid.
By the time Excalibur started, Kitty was a little jaded over heroes. Her best friends had died and she had been unable to save them; she wasn't sure she wanted to go back into the business, but took the risk anyway. It was good that she did, because it proved to be a healing experience in many ways- particularly through her growing friendship with Rachel Summers.
Kitty, who was acting mighty mature for a 15-year-old suddenly, proved that she wasn't so far advanced as to be beyond a schoolgirl crush; and that's exactly what she got on Alistaire Stuart, a young scientist who exuberantly investigated strange happenings in the U.K. The two of them were able to speak on the same level quite often, and he valued her opinions strongly, but unfortunately for both of them he had a tremendous crush on Rachel...
After the Cross-Time Caper got underway, Kitty was separated from her teammates and ended up- thoroughly by coincidence- back on their own earth. Convinced she'd never see her teammates again, she started living with Courtney Ross and eventually enrolled at an all-girls' school. Because of this it took her a little while to meet up with her teammates again once they did make it back.
When Davis introduced his new characters, Shadowcat fell at odds instantly with Feron, a young haughty mage. She hated his pampered, spoiled attitude and fought him over it all the time. Still, it soon became obvious that he was no more strong-willed than she, and we could see a friendship- and possibly more- brewing under the surface of their antagonisms. Kitty was often the only one who spoke regularly with Feron anyway.
She was extremely saddened to learn about Courtney Ross's fate, and hated Sat-yr-9 for what she did. When facing her, Shadowcat showed no mercy or affection, only anger over the murder of one who should have been her friend.
By the end of Davis's run, Kitty seemed mostly over Alistaire and was taking a few new steps in her 'search for identity'- it looked as if she was learning towards a "Linda Hamilton from 'Terminator 2'" look for a while. Who knows where she would have ended up had Davis stayed with the book?