The World's Strongest Finds a New Job After Retirement

After a meteorite struck Earth and triggered a massive explosion, spiritual qi revival began worldwide. The abundant spiritual qi allowed humanity, living on this planet, to enter a new era of cultivation. After retiring, Qin Yuan, once the world's strongest cultivator, settled down at the academy run by his younger brother. He never left the house, never went out, and did nothing but eat and sleep. He was more sheltered than a proper young lady. So much so that one time, when he finally went out, he got lost on campus. Luckily, he ran into someone: Mu Rong Qing. The youngster was in a hurry to take the entrance placement exam, but still took the time to lead Qin Yuan where he needed to go. As a result, he missed the exam and was assigned to Class D. After several hundred years of idleness, Qin Yuan's interest was suddenly rekindled. He pulled some strings with his brother and became Class D's homeroom teacher. With his cultivation sealed by a magical artifact, Qin Yuan became the teacher with the lowest cultivation in the academy, lower even than the students in Class A. The prestigious Xinghan Academy, China's most authoritative institution, admits students into four classes each term: A, B, C, and D. Students are assigned according to their entrance placement test scores. Class D is the weakest class in the entire academy. This term, it was also assigned the weakest homeroom teacher in history, turning the whole class into the academy's laughingstock. That is, until the academy's class tournament, when Class D, long the target of ridicule, trounced Class A in an overwhelming victory. When breaking through an illusion array, a Class D contestant pulled out a calculator, wrote down an equation, and quickly calculated the array's core to break it. When crafting magical artifacts, a Class D contestant brought out drafting tools, drew a perfect blueprint, and swiftly made a top-grade artifact. When refining pills, a Class D contestant used scientific extraction equipment and a series of chemical equations to perfectly refine top-grade pills. The students of Classes A, B, and C: ... After the tournament, the Class D students were interviewed and asked what had made them so outstanding. Class D students: