Limitless is a Manga/Manhwa/Manhua in english language, academy series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

The eagle soars through the sky; the fish leaps over the dragon’s gate; the bear roars and the tiger growls; all things in the world have a spirit. At the ends of the earth, the poles and magnetic fields realign; the world changes. The world we were so used to, is no longer. When myths turn to reality;