User blog comment:IamJakuhoRaikoben/Chapter 333: Man and Man, Dragon and Dragon, Man and Dragon, Review./@comment-4999650-20130531144008

I kind of recently had an epiphany where Skiadrum probably faked his death and is possessing Rogue because he wanted to be the Dragon King. I mean- It could be a way of ending the arc without giving it a climatic series feeling, I would think.

Spur of the moment thought since I didn't really look into the details but from what I remember, we don't know much about Skiadrum and he did teach Shadow Dragon Slayer Magic so I won't be surprised if he is indeed those shadows. It would also explain the entity and where it came from, since I'm not really sure how it would be explained.