Five Hundred Years Guarding the Abyss

A man from another world spends 500 years guarding his sect's demonic abyss, saving countless fellow disciples. Then they accuse him of conspiring with demons. Furious, he leaves and severs ties with the woman who trained him. The sect begins to crumble, and when it finally falls, she begs his forgiveness. After all he sacrificed, will he give it?