User blog comment:FairyRaven/Fairy Tail Chapter 370: Demons Reincarnated, Review and Commentary/@comment-5598380-20140207120330/@comment-24066070-20140208211954

Lumen => Light => Heavenly Light => Heavenly Dragon => Porlyuschka's "3 DS" prediction => Gajeel likes singing.

So, Porl predicted that when 3 DS are together(Natsu is above, but still in the same place), one of them (Gajeel) will sing a Lumen Histoire-imbued song to save them. That's what's gonna happen, believe it!