Stacy X first appeared at the X-Ranch, a brothel for mutants with unique powers that would fit at such a locale. Her powers included mainly increasing the healing of her team and the ability to seduce men or make them violently ill. While most of the mutants there did not need to touch their customers Stacy needed to have contact in order for her powers to work. Soon after the destruction of the X-Ranch by the Church Of Humanity Stacy X joined the X-Men.
Stacy X was created by Joe Casey and Tom Raney and first appeared in The Uncanny X-Men #399 (2001).
Mayor Story Arcs
With the X-Men
While with the team she continued to service her special clients which lead to a fight with Wolverine. After she was unable to seduce any of the male X-men, especially Archangel, she left the team. Her whereabouts were unknown but she was one of the mutants who lost their powers during the crisis of M-Day.
As revealed in the Sally Floyd's Mutant Diaries, Miranda became a street hooker. She worked in New York Cities Red Light District between 9th Ave. and 42nd St. She still retained a reptilian appearance, but seemed to be more scarring instead of scales. She described herself as someone hope had died in.
New Warriors: Ripcord
Sometime later she turned up as a new member of the fourth incarnation of the New Warriors, a group of depowered mutants fighting against the Superhuman Registration Act. To go with her new technological powers, she took up the name Ripcord. During her time as a member she fought against the Zodiac and the Machinesmith. She was presumably killed alongside her teammate, Skybolt, when an attacking S.H.I.E.L.D. agents' jet pack explodes.
Stacy X apparently survived her injuries against the S.H.I.E.L.D. agents and reemerged in the club scene, continuing to work as a mutant prostitute, with her mutant powers completely in tact. She was seen servicing the Ultimate Nullifier in a threesome with her former teammate Chamber's ex-girlfriend and singing superstar Sugar Kane (the trio were apparently only sexually stimulated by Stacy's pheromone-emitting abilities). The rendezvous abruptly ended when Magneto, now an X-Man, rebuked Stacy for her portrayal of mutants in their time of extinction. The Ultimate Nullifier defended the women and Stacy X and Sugar Kane escaped.
Miranda is also gifted at hand to hand combat, able to defeat Wolverine. Her skills was learned from an unknown source.
As Stacy X
Stacy can use her pheromone control to make people violently ill, increase their healing, cause extreme pleasure & increase their stamina. In order for this to happen she has to be in contact with the target. Stacy X also has scale-like skin with markings, which grants slightly increased durability. After losing her mutant powers, she still had the scaly skin and markings, which now apparently have faded away completely.
Stacy has since inexplicably regained her original mutant abilities as well as her mutated physical appearance.
As Ripcord she wears a variant of Slyde's friction suit with various gadgets including Spider-Man's web-shooters and Frog Man's spring legs.
Earth-1610 (Ultimate X-Men)
On Earth-1610, a character named Stacy appears as the girlfriend of Mastermind in Ultimate X-Men vol. 1 #81. Though there is no direct reference to this being Stacy X, facial markings and skin tone suggest this to be Ultimate Stacy X.
Later she reappears in Ultimate Comics X-Men #9 in a prison made for the remaining mutants after the Ultimatum Event, she is creating a riot about the fact that the mutants were created on a laboratory by humans and are not by natural selection. In that same prison Storm is as a consultant helping Colonel Lake and Major John Walker (U.S. Agent) about the mutants issue.