I just made a post in another thread about a potential female boss character. I think there are several ways you can run with this:
I like the idea of a female character (about Sindel's age), who appears human, but then gets spider-like qualities about her (some kind of bizarre "battle mode," if you will). The Black Widow spider is pretty infamous for its nature to mate with males and then devour them. That theme could be implemented to a combatant, whether it be nigh-literally, or just metaphorically (would you cuddle with Mileena or Tanya after?).
On the other hand, I think a young girl would make an interesting female villain. Not young as in a child, but someone who has not yet reached thirty, but has all this power. A sorceress who would make both Shang Tsung and Quan Chi her bitches at the same time. Effortless power, but a lack of maturity to fully comprehend and understand it all. A completely evil female would be too easy, but a complicated one -- who feels, thinks and has moments of doubt about her position in the universe -- but then goes and does something insane like burn a realm down with the click of her fingers, could be really fascinating.
She could walk the line between sexy and classy in her dress. It would reflect the dueling nature of her somewhat reasonable personality, and her embodiment of all wrath personality. It'd sort of be like a "I know I'm hot, and you can see that, but you know you can't get any" thing. It'd be curious to see how she dealt with villainous males that she needed for a purpose, but they completely lust after her. She'd wish she could just turn them into vapour, but they serve their purpose.
