Actually- Nathaniel isn't price charming (even though he looks like it)- but he's actually Jack Vessalius from Pandora Hearts. And furthermore, Armin isn't like Assassins Creed (because that is a video game); but rather the character Ezio Auditore da Firenze (from Assassins Creed II).
But they're all awesome! I would have killed to be there at the Japan Expo!