Pros And Cons Of Vampirism.

Ragnarok's body and soul are currently separated. He refused to fuse them so that he wouldn't become a vampire. His active rejection during the process of breakthrough led to his body and soul further separating. He is dying because his body lost the support of his soul. 

So the demon god decided to grant his body another support so that he would continue to live. But the heart of Carnage comes with more perks than an infinite supply of the power of blood and blood energy. The heart of Carnage is like the chaos spark. It comes with the power of evolution capable of creating an entirely new race as long as there is compatibility. Ragnarok's body is compatible so he began to evolve.