In the Female Villain category I take the Scarlet Witch, Wanda Maximoff.
I know, I know she is mostly identified as a "good guy", an Avenger but she initially came on the scene as a "bad guy" with the Brotherhood of Evil Mutants, led by her father, Magneto.
The Scarlet Witch can tap into mystic energy for reality-altering effects; this power was formerly limited to the creation of "hex-spheres" of reality-disrupting quasi-psionic force to cause molecular disturbances in a target's probability field, resulting in spontaneous combustion, deflection of objects in flight, and so on. She later became able to alter reality on a far greater scale, creating entire armies of enemies from nowhere. Although the Scarlet Witch has been trained in basic sorcery techniques, she lacks the specialized mystic training required to fully control her power.
http://www.superherodb.com/profile.p...=Scarlet.Witch
Not to mention that she is directly responsible for offing 99% of the entire mutant population in Marvel simply by stating three simple words, "
No more mutants". Surviving mutants and ex-mutants now refer to this as "M-Day: The worst day in mutant history". She is also responsible for the deaths of Avengers Jack of Hearts and Ant Man II among many others.
