User blog comment:B214/High School DxD BorN Episode 10 Review/@comment-26487862-20150612003703

Well, I will say, a Issei/Vali team-up would be awesome, but doubtful. Still I'm eager to see what's next.

And yeah, I think the series will end with either Issei confessing to Rias that he loves her and the final episode would end in another harem fight pr Issei and Rias getting engaged. Either one seems logical.