Because of the carelesness of the team not bothering to check up on her background, Feral's presance really caused a few problems here and there for the team. One case in paticular would be her gutting Sam in one of the teams training exercises (X-Force #2). Her bloodthristy attitude and killer instincts gave the book a real agnst feeling in its early days. Made the team seem like they were a bunch of untouchable badasses who could take on anyone no matter what the cost. All of her mischief and schemes with X-Force came to an end during a mission to rescue Henry Peter Gyrich (Nation Security Council and all-around mutant hater). During this mission, Feral was stuck with the job of carrying Gyrich out of the holding compound, during their escape, Gyrichs constant poking and pounding at Feral with anti-mutant sentances, along with Reignfires verbal brainwashing, made Feral turn against her teamates in X-Force (X-Force #27-28)
The aftermath of the battle ended up with Feral alongside the MLF, and a bitter hatred towards the world forever. She later showed up a year or so later when the NYPD put out an arrest order on Feral for the murder of her mother, siblings, and stepfather (X-Force #40-41). After enlisting the help of her sister Thornn as well as former New Mutant Danielle Moonstar, X-Force was able to capture Feral, and her as well as her sister were arested for the murder of the Callisantos family. Another year or more passed before Feral popped up again. After encountering the next incarnation of the Hellions, X-Force was shocked to find that Feral had escaped from prison and had shacked up with the Hellions. During the battle between X-Force and the Hellions we had learned that Feral had contracted the "Legacy Virus", which made her hatred towards the world even much more (X-Force #87-90). That battle ended with Feral running with her tail between her legs alongside what was left of the Hellions. But only after she had sliced open the throat of X-Force leader Syrin.
Call me insane if you like, but I (unlike so many) would welcome Feral's return to the team. She was written out after so many fans poored thier hate mail into Marvels office, but thats only because Liefeld and Niceza made her out to be a bitch. I thought she gave a stellar performance when she was with X-Force, and the book just hasn't had the same excitment without her on the team goin berserk every now and then. But after the paralyzing of Syrin in issue #90, I think its even harder to write a story where Feral would be welcome back in X-Force. But then again, Marvel does have a reputation of pulling off the impossible.