User blog comment:B214/Talk About What You Want! 2/@comment-16281343-20141029031429/@comment-16281343-20141030000941

AFAIK, tenryuu may mean Sky Dragon as used in Fairy Tail, or Heavenly Dragon as used in DxD.

It's not like they suck at translating, japanese characters may mean different things based on the context. It's just that, IMO, they take things on face value and not research about the background of the story they're working on.