User blog comment:B214/Chapter 499: Gray & Juvia/@comment-7418318-20160829143550/@comment-72.181.130.22-20160830040145

How do you know magic requires extreme concentration? Have you cast a spell before? When has Natsu ever concentrated while fighting? Gray's Ice Make and other maker magic seem to require concentration but, most character's in FT cast theirs instantaneously, which for the most part is not concentration...