Well! I covered the physical aspects yesterday, sooo. . .! Let's see. For one, it's not necessarily a bad thing to be a demon. The leader of Monoceros was a demon, actually, and he's a great guy. And then there are some like Mao, a kid that used to be on Lepus. He wasn't er, evil persay, but he was very annoying at times, and prone to experimentation. And we don't talk about his room.
The only angel I've ever known was Tailmon, but she was also a cat, and I'm still not sure how that works. But her wings were very pretty! Angels may also look like dragons, apparently.