Currently, Zero and Lucas already come to the third floor fighting those level 8 to level 10 Monsters. It has already been 2 days since they came inside of the Dungeon and all this time they are just spending their time on the third floor.
Both of them targeted the third floor from the start as they did not get that much exp and loot killing those low-level Goblins.
Zero currently doesn't have to worry about those Monsters who attacked him from a distance. Lucas handled that matter and he also handled the green shock technique. With this Zero can fully focus on his sword technique and movement technique.
As a warrior you have to say that strong heart really makes him fearless against any Monster and he can also feel that he gets some Power boost when he fights Monsters stronger compared to him.