User blog comment:Jopjopjop/Volume 20 Spoilers/@comment-178.128.187.173-20150830110103/@comment-108.224.166.119-20150902204147

No he is not a dragon god (at least not yet maybe). Diabolos Dragon was just a fusion between ophis and Issei. Best way I understand it is that it's a dragon that is sooo insanely powerful that it can only be classified as a god. Or its a god of dragons just like how the other deties (odin, zeus, etc) are gods of humans