User blog comment:St0mX/ Natsu & Dragon slayers aging theory discussion v2/@comment-7418318-20150817055355/@comment-213.238.127.153-20150817093755

Considering Gajeel's Iron-Shadow Mode read chapter 395, so he's using it. It's most likely like Nick said, that DS must be proficient in using DSM to be able to consume and use other elements.