Agiel

Agiel (Agieru) is the renown Acid-Demon and the former High-father (高いお父さん, Takai-Otōsan) of demons living in the Realm of Demons before being overthrown by his human loathing and aggressive brother, Bukavac. Ever since then, Agiel has led the mighty Rebels in battle against Bukavac's army to claim his throne and to stop him from erasing humanity. Agiel is also the foster-father of the Acid Demon Slayer, Sanki Kokuten and one of the few true Demons who uses both curses and magic.