Chronicles of the Demon Faction is a Manga/Manhwa/Manhua in (English/Raw) language, Action series, english chapters have been translated and you can read them here.
Chun Hajin, the strongest assassin of the Orthodox Murim’s Righteous Heavenly Alliance. Hajin loses his life as he tries to escape to find freedom. And then… ‘The divine cult is immortal, may all demons submit. Congratulations on your recovery, third young master!’ He was reincarnated into the body of the Murim’s public enemy, the third young master of the Demonic Cult?! The conquest of the Demonic Murim by Chun Hajin, the strongest secret weapon of the Orthodox Murim, begins now.