In the abandoned underground tunnel, Xiang Kun and Mr. Liang were dealing with a certain "mutant creature".
Yes, although there seem to be a lot of mutated creatures, such as lizards, snakes, rats, and even a mutated Asian male, this underground space is actually dominated by a single "mutant". The countless colorful mosses and mushrooms were all parts of this "mutant", and any humans or animals like the giant lizards and rats were simply hosts that it parasitized, controlled, and influenced.
When Ye Zijun discovered the moss and mushrooms that had sprouted on her face, she lost all hope, even considering suicide so that Xiao Ding could escape. But actually, the "infection" by this "mutant" was not as lethal as she had assumed. If they were not to be killed by the mutant boy or the mutant creature, once they managed to escape from underground and move away from this area - say, returning to their home country - the mosses would naturally disappear.
