OriginS is a Manga/Manhwa/Manhua in (English/Raw) language, Manhwa 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

Suijin is a bandit who has been expelled from the Gisha Walls along with two of his friends. They then live in a world where monsters are the bone of competition and battles with the walls troops are unavoidable. How's the story going? Let's read it.