My go-to guru for questions of language in Middle-earth is elvses a.k.a. Darth Fingon. You might consider registering on the Lizard Council and posing the question there or PMing him.

You've likely encountered his Sindarin and Quenya name generators, which may be found here. If I were to fumble around (and I will), I'd be inclined to go for Raucoluinon (if you want to retain the "blue") or Raucolun (rauco/demon + lun/dark). At least that sounds more like Draugluin. But again, I'm a hack. I recommend asking Darth.