Board Thread:Chapter Discourse/@comment-36009152-20200803150932/@comment-32952945-20200803171152

So Mika technically is in a dream, one step before turniing into a demon. This dream reflects on his true desires and what he truly wished for has become true and the Yu with him is undoubtedly a demon in disguise who wants Mika's true happiness.

If my guess is true, this all happened to all demons prior turning into one. For example Ashera meeting and saving Krul for Asuramaru (this is just my theory) and an example. The same happened with Byakomaru, Gekkouin, Kiseki-O etc.