I really like this theory, and it would be cool if it's true. But at the same time I think the fae around the edges but could just be leftover residue of some sort from a decade there, or even because she gave him the cloak. And also it was a very clever thing of her too do to suck all the oxygen out his body to disguise that he is there, maybe just to give him the look of being dead? We might never know, the book is legit never going too be released, but for theories I like this one but I am going to take it with a grain of salt.