The Supernatural Descends, and I Save the World with My Powers

[Primarily rule-based horror, no male lead, revenge, supernatural mystery and suspense, terrifying incidents, dangerous games] A beautiful, brilliant student at Changhua University was bullied on campus and jumped into the River of the Other Shore, dying along with the child she carried. Her story spread across the campus forums. From then on, every night at midnight, the university's abandoned teaching building echoed with a woman's anguished screams and a baby's desperate cries. Strange things began happening on the campus forums, and one bizarre incident after another drove the students to the brink of a breakdown. The teachers and security guards could never find any evidence of the strange incidents reported by the students. After the police were called in to investigate, they discovered that the beautiful, brilliant student who had jumped into the river did not exist. For a time, the students thought either the teachers were hallucinating or the students as a group were. On the seventh day after the beautiful, brilliant student jumped into the river, rules appeared in the minds of every student on campus. The teachers' eyes turned blood red, and they stopped acting like teachers, becoming cold NPCs instead. How would the students survive?