User blog comment:Omega natsu2/Chapter 371: Tartarus Arc, Part 2: Song Of The Heavenly Dragon, Predictions./@comment-3424593-20140211042100/@comment-7418318-20140211103922

Porly has no real connection to a Dragon, apart from a similar voice and smell, so I seriously doubt she's the one the title refers to. Also she doesn't seem like the singing type :P

But about the Tenryuu, I've been saying that all along, so I absolutely agree.