That's a great subject... Here are a few I can think of, although some of them might be judged borderline.

Selene : immortal mutant worshipped as a goddess since antiquity. Although her psychic vampire nature would naturally make her a predator, she relishes her power over others and acts in a gratuitously evil way.

Hela : I don't know if we can count her as a villainess, because she's just doing her job, really. Norse goddess of death, she did try to kill Thor on several occasions.

Viper / Madame Hydra : she's a war victim who conceived a deep hatred of governments at a tender age, leading to her taking over the terrorist organization Hydra. She then followed a nihilistic agenda for several years. Nowadays she seems to be more interested in money (depending on who writes her).

Deathbird: a rejected member of the Shi'ar imperial family on account of her mutations, Deathbird worked for a good long while to topple her sister who occupied the throne (even succeeding from time to time). I don't know if she's still around, but ambition and a frustrated childhood were her main motivations.

Ramona Starr (a Ka-Zar enemy). Manipulative, intelligent, ruthless, Ramona was a very efficient agent of A.I.M. who let no one stand in her way. She even forced a remote-controlled Ka-Zar to have sex with her, in a reversal of the old comic-book trope in which it is usually women who are thus assaulted!

Moonstone : a child raised in poverty, Karla Sofen swore never to let other people's needs keep her from getting what she wanted. Acting as therapist for the Captain America villain Moonstone, she managed to get ahold of his magical source of power and became a full-fledged super-villain. (She was with the Thunderbolts and the Dark Avengers, so I don't know if she's still a villain).

...and I don't know a lot about Granny Goodness, but my impression is that she had no particular origin... She's just the schoolmarm from Hell!

Agreed, it makes no sense at all. But then when she became a popular villain again a few years ago, very little of what she had been was retained... She mostly became a generic evil group leader.  (That happens with a lot of characters Michael Bendis handles... they instantly become what he wants them to be).

She was really great under Ann Nocenti's pen! I highly recommend her DD run, from beginning to end. Only Nocenti could make Daredevil vs Ultron so incredibly cool! 

As originally conceived, she was a woman with a severe multiple personality disorder, with mutant powers to boot (she could cause things to get hot and burst aflame if given enough time). 

I think she was retconned years later as being the prostitute who falls out a window in the Man without fear limited series. That particular retcon never made sense to me, if only because the character's hair color was all wrong. Evil, evil retcon spirit... get thee away from us!

Catwoman


The thing about her is that she's so complex and yet I find her very challenging and so unique that she once a supervillainess and superheroine at any given point of time that I consider her more interesting than the Black Widow and the Scarlet Witch that Rob Allen mentioned on this thread. I haven't read much of her lately but in the past she once was a member of the Injustice League and the Justice League of America and that alone makes her very fascinating character indeed. I do know that she is a love interest to Batman and married him and raised a daughter by the name of Helena Wayne who became the Huntress.

Is that the Frank Miller mini series where she is retconned? If so, my memory must be going...I read that not too long ago and don't recall it.

Iron Maiden was a mercenary, though she had shifting loyalties. Basically, she was a twist on the Dragon Lady, from Terry and the Pirates, where the character is a female gang leader who both opposes and is infatuated with the hero (DL and Pat Ryan, IM and Dynamo). The Dragon Lady was the template for a lot of femme fatale villainesses, though she borrows rather a lot from Fah Lo Suee, the daughter of Fu Manchu, who is also smitten with Nayland Smith. The French have Madame Atomos, a female scientific genius who launches a war of terror on the United States, to revenge the bombings of Hiroshima and Nagasaki. She uses various plagues and other bio-weapons, as well as other advanced weapons. She is also modeled somewhat on Fu Manchu and Fah lo Sue, though more Fu than Fah. You can add the Valkyrie, from the Airboy comics, to this list, as she was also the enemy of the hero and is attracted to him. She eventually joins up with the allies, well before the Eclipse Comics revival.

The Cheetah was another with a personality disorder, originally, and Baroness Paula Von Gunther started out as a nasty piece of work, an agent of the Nazis, before that was altered to show that she had been forced to aid them, while they held her daughter. That kind of ignored early appearances where she tortures her own female slaves.

You telling me that Catwoman was made into a Prostitute by Frank Miller ... what's on Earth did Frank was thinking and I didn't know that. This information that you shared here is unbelievable. I'm totally shocked by all this. Thanks for telling me this and this made me very sad.