User blog comment:B214/Volume 21 info & spoilers/@comment-83.26.44.182-20160509163447/@comment-27876048-20160510145804

At the question posted by anon. The info regarding Indra and Malebranche came from the author's twitter account updates, I think. Currently zxzxzx has translated about half of v21 when the epilogue or last chapter is translated then maybe there will be more info.

At second anon. There has been very little ecchi situations over the last couple of volumes maybe one at most per volume and Issei hasn't been using any of his pervy techniques lately because of the situation the series has taken on a bit of a serious tone. While the author will bring back the ecchi situations for the last arc you have to keep in mind Issei is developing into a more mature character, however he still is lecherous so if the series continues he will still be a pervert but that part of his character may become more toned down as the series goes on.