The Heavenly Demon Lord Who Doesn't Want to Level Up 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.cc fastest updating comic site. The Summary is

"Jin Yuseong, the absolute master of the Middle Kingdom, found life too boring. 'I must be crazy. Just unifying the martial world…'" "'I should have just been a farmer.'" "'No, I wish I wasn't born at all.'" "In 'The Heavenly Demon Lord Who Doesn't Want to Level Up,' one day, he encounters a gate… And upon passing through it, a new world unfolds." "Jin Yuseong, the top martial deity and leader of the Celestial Demon Cult, arrives in Korea.