I need help to find an anime.
The anime is about the mc who can transfor into a devil like being one day and his best friend returned from oversea a few days earlier. His friend has very light hair and likes to fire guns. The mc has got black hair and his body changes after he can transform himself. Both of them go on a Journey after they find out about his transformation ( I don´t know the goal of the Journey anymore). This anime is in modern times. Maybe around 2013 - 2017.
Please help me find this anime