The Pharmaceutical Chairman is the Absolute Poison Demon

Three hundred years into the future, Earth is blanketed in mana. I was a 'Mana Rejector'someone for whom mana was nothing but poison. One day, while waiting for death without ever having awakened, I connected with a soul from another dimension. It was Dang Gun-ak, the absolute ruler of the Murim world and the Absolute Poison Demon.