Song Yin could see it.
These fake Fourth Stage practitioners had something different inside them, a layer of something else above.
The one called Xu Nan at the Fourth Stage was the same, although a bit inferior to Zheng Qi in terms of mana, he also had that layer, just not as clear as Zheng Qi's.
That thing was like a beacon that gradually appeared as their realm increased until it took shape, signaling to people...
This thing, once nurtured, could be collected.
But from this beacon alone, Song Yin couldn't see anything conclusive nor could he link it with his Dharma Eye, hence his question.
"Get out!"
Seeing his move ineffective, Xu Nan's face turned angry, he stomped his foot fiercely, pointed with his fingers, and sent a sword-like stream of qi toward him.
"Eh?" Zhang Fei Xuan let out a surprised sound, showing a look of astonishment.
