Knight Under Heart is a Manga/Manhwa/Manhua in english 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

Lee Yooshin went to try out a new virtual reality game. However, it wasn't just a game. It has a 100% assimilation rate! A game world where everything feels eerily real- In the endless cycle of death and resurrection where logging out is not allowed, Yooshin prepares to fight. In order to escape the hellish battlefield from which there's no escape...