This fight was just the author wanting to nerf MC after making him too strong, it was a unique super hig tier gear yeah, but it crippled him.
I would have been fine if it was a normal fight honestly, but Kim after discovering his damage was getting reflected decided to hit harder and broke the sword, the vice was fast but he should have tried aiming for the limbs or the head with some feints, or grab the sword instead of punching it.
In short, this part was made just to make the MC weaker and the fight against the dragon more dangerous.
What happened instead? It made readers think MC is retarded.