Serving Sheng is just; Mie cannot exist independently; Mie must be parasitic on Sheng.
All Mie, before meeting people, will put on makeup and disguise themselves as Sheng.
Perhaps it is to redeem sins and ascend to heaven, perhaps to accumulate points for a next life, perhaps to welcome the Greater East Asia Co-Prosperity Sphere, perhaps to bury one's child to serve one's mother as a filial son, or perhaps to trade one's status for a higher position.
Regardless, if we only look at behavior and results, it is not difficult to infer the underlying purpose, and thus its Sheng or Mie nature becomes self-evident.
Sheng leads to Mie, and Sheng also leads to Mie; Mie leads to Sheng, and Mie also leads to Sheng.