User blog comment:Miskos3/Fairy Tail Chapter 385: The Celestial King vs. the Underworld King, Review/@comment-23887466-20140523115813/@comment-2214433-20140523124406

Underworld King is Crunchyroll's translation which is what we use for chapter titles, while Demon King comes from different source.

I've been saying for a while that we should make sure that there aren't different names of the same thing in different articles, but alas...