No. 4 Middle School, evening.
"No wonder I felt something strange earlier…" Su Yu muttered as they stared at the No. 4 Middle School in front of them. "The yin energy earlier is mixed of natural and unnatural." He told Nie Fan.
'natural' and 'unnatural' yin energy. It seemed strange but there really are different types of energies, including the yin energy. And these energies have different kinds. For one, the natural yin energy is the yin energy created by the creatures and everything here on earth. For example, the women have yin energy in their bodies. Another example is the yin land. In short, this is the yin energy from the creatures and everything of the earth.
