Board Thread:Questions and Answers/@comment-68.58.149.38-20151028025807/@comment-25942629-20160101033428

At the end of chapter 40, Yu is transforming into his angelic form in a great beam of light. The anime used fire instead and was liberal about changing quite a few details. He has yet to become a demon. There are raws floating around on the Internet that may or may not be true, but the official English chapter won't be released until January 11th. Fan translations are typically unreliable to a certain extent, but they are available. It would normally be released January 4th (the first Minday on or after the 4th), but it's been delayed a week because of the holidays.

In the raws, it looks like Yu has lost his humanity as promised and is now trapped in the form of a demon. However, this information is unreliable, so I just recommend waiting until the 11th.