Ophiuchus Is on Top

[Paranoid and yandere male protagonist + double-faced wolf-killing female protagonist] I was born in the Year of the Snake. I was born with an incomplete soul, lost all five senses, and suffered from a strange disease. In order to keep me alive, my grandfather took the inner elixir of a black python that shed its skin and turned into a dragon. I survived, but the python has been haunting me since then, turning into a man wearing a black shirt...