(Synopsis from the back cover):
«"Who am I?". A devastating dungeon break at his sister's high school is quickly taken care of by Jinwoo...but not before he confirms that magic beasts no longer register him as a human. What's more, the deceased Byunggu Min sends him a cryptic warning from beyond the grave: Jinwoo's powers are more frightening that he knows. Left with too many questions and very few answers, his final hope lies in the key to Cartenon Temple. Jinwoo's determined to find out who—or what—he's become, and to do so, he's prepared to return to where it all began!»
One of the scenes involves an orc attack on a high school; it's quite shocking. A magical portal appears in the middle of the school, and orcs start pouring out of it right in the middle of class time. It can be quite disturbing and unsettling; it feels pretty bad.
In this installment, some answers finally begin to emerge to the many questions surrounding the mysterious "System."