Board Thread:Questions and Answers/@comment-27545423-20160203222642/@comment-25942629-20170225152745

It's pretty common for people to become demons after coming into contact with one. Yoichi temporarily becomes one at the beginning of the series. In the Catastrophe light novels and in the Vampire Reign manga, Takaya Kagami mentions how they have to kill students and soldiers who lose control and become demons.