I'm doubtful that he dies in one hit like that. Could be a shadow clone or he might just have some regeneration techniques. Either way I bet hes going to be weakened enough that he cant just crush anyone who messes with the MC but still powerful enough that he isnt a burden.
there's something weird, how did the henchmen get past the 3 of them when they were clearly standing in the way and told the convoy to retreat? Seems like they just got killed for MC to get more motivation to fight evil in murim