Magnificent Bastard: Marc Remillard, to a point. Sometimes he seems quite reasonable and gentlemanly and charismatic, but let's not forget he caused the deaths of four billion people, turned his son into a fish, and is STILL trying to find another world to take over to use for his Mental Man scheme- might I add that this involves creating a civilization of bodiless brains?
Aiken Drum is also a Magnificent Bastard, at least as far as the Tanu are concerned - he outplays them and the Firvulag at almost every turn. Marc beats him only because he's older and better at the game.
Woobie, Destroyer of Worlds: Felice; YMMV somewhat on how much of a woobie she is. But for a certainty, bad things happened to her and tipped her into raving insanity (and power).
Values Dissonance: Julian May is impressively vitriolic about transgender, seeing it as a blasphemous obsession with female power; the human Quisling who figured out how to reverse the sterilizations of Exiled women so the Tanu can cross-breed with them is a male-to-female post-op transsexual. In-Universe, 100% transgender modification is utterly impossible, and "he" has turned "real" women into Baby Factories because "he" can't get pregnant "himself" and thus sees the breeders as proxies;
"Oh, you could stow away some real woman's fertilized egg in her fake uterus, and maybe shoot her full of preggy hormones, if you could get them in this primitive world —- and perhaps the embryo would live a few weeks before dying. But that's all, lover. Maternity is a marvelous and tricky symbiosis. And of course, no one in our Galactic Milieu or anywhere else has ever made a true mother out of a male."