My professor is an S-class anomaly

Twenty-one-year-old junior Noah Reyes wakes up trapped in a midnight make-up exam. Breaking rules, failing or leaving without permission earns an F—not just a bad grade. F-marked people get wrapped in exam papers and erased. A romance survival system gives the only escape: seduce invigilator Lucian Vail, an S-class entity who can write fatal Fs with a black pen. Noah schemes to steal the pen and exploit rules, yet genuine love blooms. Lucian, once a failed student turned monster, bends his own rules to protect Noah.