User blog comment:B214/Light Novel Volume 16 spoilers/@comment-1392308-20131019074749/@comment-1359322-20131019081853

Well he already gained an improved version of the Dividing Gear when Ddraig and Albion made up. So maybe if Issei can befriend more Dragons and maybe put something from the Dragon, (maybe the scales) into his Boosted Gear, Issei can then somehow use the Boosted Gear to channelled them into his body.