Hideo Asou is a Catholic priest who is known to be traveling with Ron. Asou seemed to have been affected by the virus when it was "Nightmare Week" and he, Ron and another child were hit together by the virus. Asou gains the power of petrification, which allows him to turn people into lifeless stone statues merely by touching them, a process that cannot be reversed except by Taisuke's unique abilities. Asou uses this power in conjuncture with his skilled martial arts to get close to his opponents to touch them. When the child who has been infected attempts to hang himself, Asou tries to save him, but unintentionally turns the child into stone instead. When the other people see this they become afraid of him and lock him inside the church. Then he meets Katsumata and tells Katsumata to kill him. Katsumata uses his power and alters Asou's mind into working for him.
After Hirose absorbs the "Heart of Akura" Asou kills himself by petrifying himself.(Source: Wikipedia)