Why would there be devil energy here?

If it were someone else, they would only treat this as a yin aura that naturally occurred at the bottom of the deep abyss. However, Yun Che had fought Fen Juechen and Xuanyuan Wentian, as well as interacted with an actual devil within the Moon Slaughter Devil Nest before. In one instant, he could tell that this aura was the same type of aura as the devil aura on the Moon Slaughter Devil Sovereign!

However, this devilish aura was exceptionally ...