Poison Ivy, Killer Frost, infectious lass.
Basically the appeal is the idea of someone being able to use their feminine wiles for domination or deadly purposes. Conceptually the more deadly the woman the more alluring it is to me. Ivy in particular is not only highly toxic, but can control her toxicity and prefers to deliver it via kiss. Not only is it dangerous but it means that the longer/harder she kisses you, the more dangerous it is. It's basically death by intimacy.
There's just something so enticing about a person who is deadly in a very real way. From her saliva to her blood. Rather than a physical strength it's an internal infection, meaning she almost always has an upper hand in close quarters.
tl;dr Poison women are perfect for femdom and playful snuff.