Yajin Tensei: Karate Survivor In Another World is a Manga/Manhwa/Manhua in english language, Adult 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

If you're reincarnated in another world, you will be naked and alone in the forest. The only things you can rely on without magic or cheats is your wits and fists!