CLASS DEATH RULES: Violating class rules results in death

Upon entering the new class, I immediately noticed the class rules posted next to the blackboard, all written in red paint with a few bloody handprints around them. At the same time, a message was sent to the class chat group, stating "Please remember the class rules. Failure to comply may result in a life-threatening situation."

I wondered if it was just a prank. However, strange things kept happening, and students who broke the rules started dying one after another. What is the connection between these incidents and Nailah Fuchs, who died three years ago?