College Brave Representative

My name is David Ke, a useless college art student who failed English, was at the bottom of physical education, and fantasized about being reincarnated into a different world all day long. His name is David Cortex, a Templar warrior who bears a blood feud and is about to fight the dragon to the death. Yes, we have the same name and surname. Then at the moment of the decisive battle - we exchanged souls. He came to my university dormitory and faced exams, physical tests, and professional courses that he didn't understand. I fell into his different world, facing a giant hammer, a magic knife and a black dragon called "Goliath". He said: "Please take my place and defeat the evil dragon." I said, "Please help me pass the final exam first." In a month, all his friends will be dead - unless I can find the answer in his body that changes their fate.