User blog comment:Mangetsu20/Four Battlefronts...not a Star Wars reference (FT - 462)/@comment-3045936-20151121225522/@comment-4326112-20151122064908

I'm not sure if Bickslow ever used his eyes to see Natsu's soul. I mean, since it's been a long time, possibly. But I don't remember an episode where Bickslow had looked Natsu in the eye. At least, not up front anyways.

Perhaps its because Natsu is such a deranged hybrid of character races/traits that he won't be seen as naturally human anymore. I mean, his battle with Mard Geer showed him almost become a Dragon-like being so to speak. If anything he's more of a Dragon than a Demon could be