A Psychopath With SSS Rank Class

On Terrubis in 2308, numerous portals have been opening for over 1250 years. Initially, these portals posed significant threats, and the beasts emerging from these dungeons were dangerous enough to destroy the world. Firearms had no effect on these creatures. However, humans began to awaken and unlock classes, and these individuals were named adventurers. This story focuses on Asura Lock, a completely normal person... who only killed his family at the age of seven... and also enjoyed killing his family... I suppose those are just details. He was locked up in a psychiatric hospital and should normally remain there for the rest of his life, however... --------- The protagonist is truly a psychopath, with no reason for the murders he commits. He has a totally different vision of justice and life in general than other humans.