Help Me Find This Book, Everyone: A TikTok-Recommended Quick Transmigration Novel with a Universally Adored Protagonist

I haven't read it. One of the small worlds is about the protagonist, Yi Nian, at university. His classmate Kang Ning was murdered, and Kang Ning had been following Yi Nian and taking photos of him. The police deduced that the killer was punishing Kang Ning. The protagonist then wants to find the killer. This small world has some horror elements.