What is the effect of Piety commandement? I've been watching the seven deadly sins for some time now and in recent episodes (trying to avoid spoilers) there's a request for Zeldris to release people under de Piety commandement.

My question is, what are the effects of such commandement? 

We've seen people turn to stone for not abiding to a commandement, etc...
As read on the wiki article on commandments


  Piety「敬神 Keishin」
  Anyone who shows their back to the wielder will become an obedient slave of the Demon King and by extension, his representative and youngest son, Zeldris.