Quantum herself
Quantum Flannery
Doctor Insidious
Quantum: A toughie. We know very little about her past and what we've seen of her is pretty much pure evil.
That said, given her meeting with Faith, there are hints of a past there and for all we know they may have been friends once. Just what exactly happened between them that Faith never mentioned it?
Flannery: The FLAN!
Practically the opposite of Quantum, she's a full out hero. Now, we have seen that, when really mad, she can be almost comparable to a force of nature, as the gang that busted up Matthew found out. I guess the only real question I can come up with is....is she doing it just to be a hero or is she trying to follow in mother's footsteps or because of guilt over what happened to her father or some kind of combination?
Insidious: Just why IS she a villain? Is it because she was raised to be one or is she just having fun with it? While she does have a rivalry with Power Woman and a bigger one with Nemesis, she's shown to be pretty civil with the heroes, even coming out of nowhere with a Big Damn Heroes moment against Harbinger. She also slept with Nemesis and they were both pretty happy about it in the morning. We have glimpsed her past and it's been hinted that she's been through some pretty messed up stuff. She also said that she's done some arms dealings with lower level criminals to help them out. Contrast with Nemesis selling weapons to much worse criminals just for profit.