동료를 살해했다는 억울한 누명을 쓰고 사망한 카시안. 모든 게 끝이라고 생각한 순간. 그의 영혼은 어느 소년의 몸에 빙의되어 빌런으로 각성한다.

There are two kinds of people with special abilities: villains, who are driven by their evil desires, and psykers, who pursue justice and work against villains. Cassian Lee is a very powerful psyker with a good heart. But one day, when he visits his friend in Greece, things take a wrong turn. Following an unexpected chain of events, Cassian ends up in the body of a Korean high school boy… who has just become a villain! Will his sense of justice win in the end or will he end up becoming a cold-blooded villain?