User blog comment:IamJakuhoRaikoben/Chapter 450: Alone in all the World, Review./@comment-3424593-20150831044341/@comment-7418318-20150831073110

Well... Mavis death might have very well contributed to increase his instability further. He opened his heart to her and had it ripped out of his chest as a result.

As for Mavis, I could imagine being killed by him might dampen the enthusiasm of her love for him quite a bit too.