The Underworld is Empty, Yama is Teaching 38

After "retiring," Xue Changyi, one of the Ten Yama Kings, arrives in the parallel world's Jixia Academy—Underworld High School—to become a substitute homeroom teacher. Xue Changyi is proficient in burning livers, skinning and boning, and capturing souls. He has killed, beheaded, and judged, but… he's never been a teacher. Underworld High School, Class Nine, the legendary experimental class. Class President Qin Shi Huang, Study Committee Member Zhuge Liang, and troublemaker Lü Bu. Liu Bei from the next class comes by daily to sell straw sandals; the poet Li Bai attends class every day with a wine pot and sword; and there's also the tyrant Emperor Yang of Sui, now a classmate, and his beloved father, Emperor Wen of Sui, making parent-teacher conferences incredibly convenient… Yang Guang, the Sui Emperor, who hasn't turned in his homework: "I am the Son of Heaven, the True Dragon Emperor! Do you dare strike my hand with a ruler?!" Substitute homeroom teacher Xue Changyi blinks: "We can skip the ruler." Yang Guang sneers. Xue Changyi ponders for a moment, then takes out his Divine Striking Whip: "Spanking, however, is an option." Yang Guang: "..." One day, in addition to selling straw sandals, Liu Bei expands his business—selling best-selling novels! Underworld R1800+ rating, annual sales TOP1! For 200 consecutive years, the reigning sales champion! Highly recommended by the poet Li Bai, a mysterious and forbidden love story!