Humanity has lost. By the end of World War Three, the R-virus has decimated 80% of the world's population. To make matters worse, the virus transforms the infected into mindless monsters who crave human flesh, with some evolving into powerful beings with special powers called "Rayers." The last remaining human settlements live in fear, their survival entirely dependent on the R-X, teenagers who have gained special abilities themselves through contact with Rayers. Wielding lethal weapons and supernatural abilities, the R-X fights to defend what little hope humanity has left. (Source: Webtoon Entertainment)