User blog comment:IamJakuhoRaikoben/Chapter 462: Battlefield, Review./@comment-99.65.101.58-20151118053802/@comment-1359322-20151118085646

Actually in this case he is using his head (to a certain extent). Natsu (to his own credit) claims that he has created a move that can supposedly defeat Zeref. Now if his move successfully defeats Zeref then the war can be halted or at least the tide of the war can be turned, well the new move he has probably won't work. So while it's not the brightest move from Natsu (using a move which effectiveness isn't known), it's not a dumb move like most think, cause if it succeeds then the morale of the Alvarez Kingdom entirely and help increase the survival rate of others.