Review Detail of PakCikZen in My Passive Skills are Invincible!

This novel has a good story, but somehow after chapter 173, MC become so stupid, arrogant and careless, it's hard to continue reading. And the OP weapon he had was given to his disciple, even after it was stolen due to his disciple's carelessness. Not to mention that he suddenly become a coward, even though his passiveskills are still there.