User blog comment:IamJakuhoRaikoben/Chapter 503: The Last Sight Seen, Review./@comment-84.197.239.101-20160926192137/@comment-5303512-20160927175934

What Gajeel said is basically up to individual interpretation as in he could mean that he doesn't sense Magic Power at all. Besides that, the proof is that Bloodman explicitly stated himself that he doesn't use Magic Power, but uses Curse Power, read the chapter again. Just like how humans can use curse powers too.