Spiral's real name is Rita Wayword, a.k.a 'Ricochet Rita', a professional stuntwoman who befriended Longshot when he first appeared on Earth. The story of how Rita became Spiral is a paradox: Rita was attacked by her evil, future self which led to her meeting Longshot and falling in love with him. When Longshot sought to return to his home dimension, the Mojoverse, the lovestruck Rita went with her boyfriend, only to watch Longshot fail and be captured alongside him by the dimension's evil overlord, Mojo. Longshot was promptly mindwiped to forget all about Rita, while a much worse fate was left for Rita.
After holding her prisoner for several years (at which point Rita was made to serve as guardian for Mojo's army of "X-Babies"), Mojo forced his chief scientist, Arize, to perform extreme physical and mental body modifications onto Rita to recreate her into a loyal subordinate. These experiments left her with six arms (some of which are robotic), turned her hair grey, and drove the young woman insane through forcibly evolving Rita's mind to the point that she could see into other dimensions that were used for time-travel/teleportation. He also trained her in the dark arts of magic and body modification, so that she could use these skills to mutilate others like Mojo had mutilated her. Finally, in a cruel act of manipulation, Mojo sent Spiral back in time to set into motion the events that led to her former self becoming Mojo's prisoner and become Spiral by attacking her past self.
Now in the past, Spiral found herself stranded on Earth by Mojo for failing to kill Longshot and Rita. At some unknown point, Spiral encountered Val Cooper and was recruited into Freedom Force, a revamped version of the second Brotherhood of Evil Mutants. Despite being utterly insane and more blood-thirsty than her new teammates, Spiral quickly became a valuable member of the team, single-handedly defeating the X-Men on several occasions as well as kidnapping the X-Man Rachel Summers for Mojo. She was also instrumental in Freedom Force's victory over the Avengers and the West Coast Avengers when sent by the U.S. government to arrest the heroes. Her magical powers temporarily robbed Captain Marvel of her energy powers and she also defeated Iron Man, removing two of the most powerful Avengers from the battle.
She also ran the "Body Shop", which sells alien cybernetic parts to amputees and others who see the power of cybernetic limbs. Lady Deathstrike and several members of the Reavers were some of her earlier clients though later writers have retconned Donald Pierce and not Spiral as the person responsible for their becoming cyborgs. She also was responsible for giving Psylocke cybernetic eyes, which doubled as cameras for Mojo to spy on the X-Men.
Along with Mojo, Spiral was shown to have played a role in Psylocke becoming Asian in Uncanny X-Men #256. Originally, it was believed that the two literally transformed Psylocke from being British to being Asian, but in X-Men V2 #31-32, it was revealed that Spiral (without Mojo's involvement) transferred the X-Man's mind into the body of the Asian assassin Kwannon.
Even though she was a loyal servant of Mojo, Spiral deeply resented Mojo's crass manners and cruelty towards her. In particular, Spiral has been known to go against Mojo's orders and attack Longshot out of psychotic need for revenge for Longshot's seduction of her and how her love for him led to her transformation into the being she is today. As such, Mojo has been known to leave Spiral stranded on Earth (since Spiral needs Mojo's power to travel between dimensions safely).
In the X-Force: Shatterstar limited series, Spiral was revealed to have conquered an alternate timeline and referred to herself as "The Apocalypse". She managed to kill most of that Earth's heroes, and only Cable and some of his X-Force/New Mutants allies were left. Spiral had kidnapped that universe's Sunspot and tortured him by making him make love to her until his rescue. With the aid of Shatterstar, Spiral was evidently defeated and apparently returned to Mojo's services. She later attacked the X-Men together with Mojo, but ended up defeated once again.