I'll be good and not comment about the "horns". (Damn it! I think I just did!) As a little feedback, and opinion, Dark Millie has to have that creepy Elly-on-Drive expression, rather than soulless eyes and demonic theme. The "I'm going to mess you up, bitch!" look while simultaneously being apathetic about it.
I won't say anything about Mytoss, aside from provide numbers to a number of PhD's that would love to take a look inside his head and see how the hell he can manage to function on a day to day basis.
That said, I think with your artistic skills you're allowed to a little conceit. Show us Laladilya; you have to make a cameo somewhere.
