Please, graduates, slay the demon!

Humanity, fleeing from the northern wilderness, erected towering walls that reached into the clouds, keeping the dangers that had threatened their ancestors for millennia at bay... And so, peace reigned. Until one day, a thick fog swept over the walls, descending upon human cities. The danger within the fog gradually surfaced, and humanity was once again reminded of the fear of being dominated by a great demon. The great demon's arrival—this was the worst of times. The Martial Arts Era—this was the best of times. Chen Yang, sword in hand, stood atop the towering city wall, gazing at the danger within the fog. "Who are you?" a voice from the fog asked. Chen Yang raised his sword, standing before the myriad lights, and replied, "I am a high school graduate who regrettably failed his college entrance exams."