Vapor

Vapor is a supervillain from Marvel comics and a member of the U-Foes - a group of criminals who act as a kind of evil-version of the Fantastic Four.

History
Vapor's history prior to being recruited as a technical specialist for his space mission by Simon Utrecht has yet to be revealed. She, along with her brother James, was among the small group led by Utrecht to simulate the crash that gave the Fantastic Four their powers, and has remained with the U-Foes ever since.

Alongside her teammates, she has had encounters with heroes including Hulk, the Avengers, Spider-Man, Crossfire, Puma, Darkhawk, and Portal.

During the Acts of Vengeance, Vapor attempted to kill the Scarlet Witch.

Vapor and the other U-Foes were recently recruited to serve Norman Osborn in his scheming, and have since joined the Hood's Gang.

Powers and Abilities
Vapor is capable of transforming her body into any type of naturally occuring gas, including mono-molecular mists. Although not much can harm her physically, she is only able to return to human form for brief periods of time.