Dead Rock is a Manga/Manhwa/Manhua in english language, MONSTERS 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

The latest series by Hiro Mashima is a Demon World Academy Dark Fantasy!! DEAD ROCK is a demon king training institution that towers over the depths of the demon world. Yakuto, a young demon, challenges the harsh entrance exam to knock on the doors of DEAD ROCK!!