If there's a superhero game running that could use a one shot plot I have a villainess. Or, if there isn't one I could start one.
Cherrity Hancock is an aether-ship pirate captain. She travels the aether (kind of like sub-space) going from star to star pillaging and ravaging for technology. If they are a magical based society she attempts to obliterate them (she loaths all things magic). Before she begins her campaign though she tends to abduct people and interogate them and, possibly, induct them into her crew.
Most of her technology is steampunkish but Earth is Earth but with superheroes so the technology can be anything (like Marvel or DC universes).