User blog comment:IamJakuhoRaikoben/Chapter 503: The Last Sight Seen, Review./@comment-84.197.239.101-20160926192137/@comment-5303512-20160927210941

Again I said that from how they said it, Gajeel had no idea what to expect from this guy, he was expecting to have equal power to the rest of the twelve but didn't, and based on his personality, he likes to insult others. And with Bloodman's response, he was correcting Gajeel's ignorance by stating that he uses Curses, there is nothing that states that he confirms that he may have low magic power but makes up for it with Curse power, all he states is that he just has curse power.

Mira can use curses even though she is still human, no matter what form she takes or what power she users, at the core of her character she will always be human.