There are a few half-vampires (turned by the Red Court, but don't become fully vampiric until they kill someone and drink their blood).

Changelings- half human, half fey. They're as likely as any human to be good or evil.

Religion- or rather, the power of pure, strong belief- has power. It can turn back Red and Black court vampires, and there have been examples of people performing miracles in the book.

Finally, there are... non-main characters. By which I mean, Harry Dresden is a Wizard, Capital-W. He's young, but he's still on the Council, which is like having a black belt, or maybe a PhD. There are plenty of people with not enough power to make the council, or maybe just the ability to do one or two specialized things. We're in Chicago's supernatural bar, so it'd be completely reasonable to find someone who can only speak to ghosts, or only manipulate sound, or maybe a small coven that can't do anything too impressive, but by pooling their talents can cook up a couple of interesting effects.