As You Xu's good friend, Lu Feng had caused Zhang Xuan a fair bit of trouble back in the Master Teacher Academy.
However, with the revelation of Zhang Xuan's 'identity', the grand appearance of 'Yang shi' in the Elder Hall, and his confirmation as the next principal of the Master Teacher Academy, Lu Feng had been punished, and he had disappeared from the academy.
According to School Head Mo, Lu Feng had voluntarily applied to head to the Subterranean Gallery in order to redeem himself, and it was very likely that he would never return.
Back then, it had left Zhang Xuan in deep thought for a long while.
Given how large the Subterranean Gallery was, Zhang Xuan had thought that it was extremely unlikely for him to meet Lu Feng. Who would have thought that he would encounter the other party shortly after entering the Subterranean Gallery and find them cornered?