A stunning woman in a skimpy blue unitard, Vapor wanders the city, a scourge of the criminals in New York City.
She's very tall and blonde, with a very sensuous figure and an inviting smile.  Her identity is a mystery, and she seems to enjoy flirting with fellow heroes and villians alike.
Her playful manner seems at odds, nowever with a mean streak that makes her combat with enemies somewhat savage.
Her powers include insubstansibility and a powerful buzz-saw punch.  Some have wondered if the similarity means that she and Shimmer, the UNTIL hero.
When asked, both are coy about a possible relationship.