I Took Over the Demonic Sect Master is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

Once Wang Bai awakes, he realises he’s somehow crossed over into a fantasy world, and that he’s even lying in a coffin! After receiving a portion of his memories, he realises that this body is the sect master of the Demon Sect, who has committed unthinkable crimes and made millions of enemies. Worst of all… he has lost all of his cultivation, and his previous disciples who harbour ill intent towards him have all become big shots Σ(っ °Д °;) the Ruler of the Palace of Five Poisons, the Lord of the Temple of the Demon God, the Leader of the righteous Way… should I just lie back down in the coffin and never get out?