User blog comment:B214/High School DxD EX/@comment-24053170-20160113224250/@comment-24053170-20160114165217

I don't know why you think Ophis isn't part of his harem when the author himself said otherwise?

He didn't want to add her to the harem at first, but when he saw her he decided to do so.

So yes, she is a member of his harem according to word of god.

and great red and ophis will never happen, not even in this insane series.