Im not saying that he should be nice to his enemies, but rather talk while thinking. The major skill he has right now is plot armor, and reading the novel made me realize how he would survive if he was not the MC. For example and Spoilers,
there was a floor where 3 boss monsters came to try recruiting him and fight against the creator of the game, but instead of carefully talking, he just said to them to shut up, then he was chase by 3 bosses.
What frustrated me is how I didnt got to understand the enemies motive because he quickly shut them up. It was a good opportunity to get information but he chose to be aggressive and lead on his near death experience but the plot armor still save him.
When talking to tel: Shut up and Go!
When talking to the enemy: F*ck you, just die
He has no sense of someone who issuperior than him and speaks to enemies disrespectfully when he is only a player and has not gained much power to interfere with this crazy missions or floors.
Im afraid that his going to die due to his stupid mouth.