Board Thread:4. General Discussion/@comment-124.83.16.225-20160127164816/@comment-124.83.16.225-20160226102523

Rotten Purity is just me translating the kanji separately one after the other, but I took the rotten kanji to be an affix to the kanji for purification/cleansing/purging. That is, instead of purifying something to be completely clean, it's purifying it to be "rotten" 100%. If it helps to put it into an analogy: a mixture is 50% substance A and 50% substance B. For it to be pure substance A, it must be composed 100% of it. Likewise, for it to be pure substance B, it must also lack any % of substance A. In this case, A is "non-rotten" and B is "rotten".

Forget the conventional meaning of "purity" and think of the "rotten" kanji as perverting its natural meaning. Given the context of the hero and the gods for "rotteness" being all fujos, the interpretation of it meaning "completely rotten" seems apt since that's how some fujos talk about themselves (well, how they talk about themselves in anime and manga).