Who is that old man with yellow teeth?

This old man with yellow teeth who covers the sky is a role in the San Qian Road of Wuying in fantasy novel, and he is a great Taoist elder. Huang Ya, an elder of Daozong, usually guards the pavilion of the sacred peak and later becomes the Lord of the Ten Peaks. I don't like Mo Daoxian's character. I care about Xu Wuzhou's superb qualifications and hard work, but I also hope that Xu Wuzhou will not be too conspicuous and teach him supreme martial arts all the way. Taoism is one of the few people who know Xu Wuzhou's true character.