I Was Going to Save the Whole Class, but I Was Transformed into a Primordial One

I wake up to find that nearly everyone in my class has been turned into a vampire. Together with a few others, I fight the vampire leader. Just as I'm about to obtain an important secret left behind by my senior, I'm discovered and captured, on the verge of being forcibly turned into a vampire. In the nick of time, I accidentally reverse-feed, absorbing the pheromones of a powerful vampire and becoming the vampire leader's first servant, taking the number four spot. Then I discover that my senior has become number three. Only powerful vampires can retain their will. Has she forgotten everything, or does she still remember? Will I be blinded by power and join the vampires, or secretly take revenge and save the whole class?

This novel and its characters are entirely fictional. Any resemblance to actual people or events is purely coincidental. Do not imitate.