User blog comment:B214/Volume 23 discussion blog/@comment-175.136.214.240-20171016073623/@comment-103.27.61.101-20171027040104

You will see that at the start I focus on the point that Issei wants to destroy half the map, not the pocket dimension but he has to use dxd mode so he is weak because dragon blast is enough to achieve the same result but B214 convinces me why Issei uses dxd mode.