





The real reason why Hanaki lost
Hanaki had a Z-Gun, but he didn't use it.
As shown during the battle, Hanaki exhibits sadism. He likely abandoned the Z-Gun to kill his victims more slowly, just like the Sadistic Trio did.
If Hanaki had his Z-Gun when he faced Nurarihyon, he would have dealt more damage to the boss and had more time to escape while Nurarihyon regenerated.
Of course, Hanaki's panic also played a role, but I believe the Z-Gun would have increased his chances of surviving this fight.