What happens to the person who wears bodhisattva guanyins cassock ?

The same treasure is passed on to Sanzang before he embarks on his journey. The brocade cassock is a protective ornament and the person who wears it has the ability to send demons back to hell. The cassock is a very powerful ornament created by heavenly immortals and is only meant to be worn by a true monk...Sanzang later loses the brocade after other monks conspire to kill him. The cassock is stolen by the Black Wind King. Sanzang’s disciple Sun Wukong tries to fight the Black wind King but is defeated. He eventually seeks the help of the original owner of the brocade cassock Bodhisattva Guanyin who converts the Black Wind King.

Hope that helped =)