Demon Gate's Forgotten Guardian

A son of the Lin family held the Demon-Slaying Pass for a hundred years. In that time he reached the Divine level, and with 800 hunters under him the pass was never taken. Then his parents came to him with a demand: hand every one of those achievements over to his brother Lin Chen, so that Lin Chen could command the pass, marry the princess and take the glory. He signed the paper that cut him off from the Lin family and left. The Lins claimed the credit. Lin Chen was given the title of King Jingzhong. Some time after that the demons attacked in force, the Demon Emperor appeared, and the pass fell. The family that had disowned him came to his door and knelt there, asking him to save them. He had spent the years since in seclusion and had gone past the Divine level, and he came out to face the Demon Emperor.