Well since I thought it might be a bit hard for some of you to imagine a voice that sounds BOTH feminine AND masculine I thought this might be best. Although if you actually DO manage to figure out where these voices are from I'll have to just give you credit for being as obscure and weird as Meg and me.
Panderas -
Damaged- Spooky alternate version of Mz. Bitterz from Invader Zim 'Halloween Spectacular of Spooky Doom'
Young and emotional- Audri from the movie Moulin Rouge
Young and detached- The Japanese voice for Kenshin in Samurai X
The Seven Sins and Virtues-
All respectively- Gir from Invader Zim
Fredrick-
Before transformation- Terry McGinnis or Batman from Batman Beyond
After Transformation (normal)- Marc Wordman or Ironman from the animated film Ultimate Avengers
After Transformation (pissed)-The computer from Invader Zim in episode 'The Frycook what came from all that space'
Julian (as Meg has decided to do Alexis)-
Before Transformation- James Marsters y'know he played Spike in Buffy and Angel
After Transformation- Joker from Batman the animated series (as well as every OTHER animated show he popped up in before THE Batman)