OHOHHO, Natsu was too Reckless this Chap for sure, charging into the main enemy forces like it's nothing, and he got that serious expression too, i Think that he met / fought zeref in the past year, and he awaken somekind of black magic and he hid it in his arm, that's why he said "let's finish what we started, zeref", and before attacking Avatar, he seemed familiar with Zeref and his followers, i hope we find out soon enough
I WANNA SEE NATSU UNLEASH WHATEVER HE HAS UNDER HIS BANDAGE AND INSTA-DEFEAT 2 of the spriggans, that's gonna be epic :D