Decay. Rot. Bile. Blood. These were the only things that scented the air of these floors. For someone with Beastman blood like Lucius, the Undead Plains crippled one of his many advantages in a fight. When everything smelled like death, it was hard to tell where more of the fresher ones still lurked.
His advanced hearing was not all that much help either. Since zombies and skeletons had no reason to move unless they were tracking something, they stood stark still. They did not breathe and they had no hearts to beat. Not to mention the only ones that possessed Mana were higher-tiered undead with the ability to cast magic. On early floors, it was unlikely to be something they ran into.