The Rebirth of the Demon God is a Manga/Manhwa/Manhua in (English/Raw) language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

The demon leader Di Shi Tian was betrayed by his most trusted friend, and perished under the combined attack of the Five Sects. When the world thought they had vanquished the demons, Shi Tian is reborn as a student Mo Fan. Without his powers and abilities, and under the attack of the Five Sects, Di Shi Tian starts his journey of revenge.