I think it's a little hard to pin to pin down cards as good or evil- as their backstory basically requires a reason they'd be fighting every other clan out there, no cards are strictly good or bad. I mean, you could argue Fang Pi Clang and Pussycats are both evil, as one is seeking world domination from a Bruce lee clone and the other is supposed to be outright sexist (some characters are portrayed as merely feminist, but according to the clan description they view men with outright disdain). Oh, and I would count Nightmare among the classical 'evil' clans before I'd put in Piranas, and Freaks are usually thrown in there too.
But including the six you listed and the other two usually a categorized as 'evil', that puts them at eight, and most the other clans are in the grey area rather than on the light side. That aside, the underground reptilians idea would be fun to see, and I may have mentioned something to that effect earlier.
How about a clan full of drunken people? Perhaps a drunken russian clan xD
Well these also sound nice:
- Political Clan
- Gamer Clan
- Dwarf Clan
- Ninja Clan with no artwork at all, since you can't see ninjas
- Medieval Clan
- Dinosaur Clan
- Superhero Clan
Anyway, I'm for the drunken russians clan.