Hugo refused, "No way, Han! Let me follow you, please?"
"Not today, Hugo. It would be best if you fully rested first and..." Lee Han paused while taking his crossbow from his inventory. "You learned how to use this in the corridor. I need you to master this weapon as soon as possible because you'll need it tomorrow."
Lee Han couldn't risk Hugo's safety if he followed him now when Hugo was obviously not in his fittest form and ill-prepared.
Besides, Lee Han would stay outside until nightfall, when the temperature can be deadly freezing. With his shield, Lee Han can withstand freezing temperatures. The same thing can't be said about Hugo. He doesn't have an invisible shield like his.
Hugo evidently didn't like the idea that Lee Han had to leave him in the comfy of the invisible and protected building. He was distraught that if something terrible happened to Lee Han, which made him never return, Hugo would have to stay in this strange place alone for god knows how long.
