Heavenly Vow

Heavenly Vow (天劫之誓, Tiānjié Zhīshì), lit. "Vow of Heavenly Calamity", is a heavy oath that can't be destroyed and can only be sworn once in one's life.

The vow takes ten years off the oath taker's lifespan. If the person were to go back on their vow, they would face a heavenly calamity and disperse as dust on the wind. Because of the severe requirements, there are only a few people that took the vow, including Mo Xi.