It's funny how Krebskrum has to hide her Demon King appearance, yet Diablo looks pretty much the same (horns) and even proclaims: "I am the Demon King" every opportunity he gets.
@Umetsu : I've been wondering about this for a while... but does anyone have what the original Japanese terms for those two phrases were? The way it is translated into "demons" and "demonic beings" is really misleading... as frankly it just sounds like two ways of saying the same thing to me.