Zhu Kang clearly felt the change in Lin Yifan's strength. This feeling, seeming both real and unreal, made it difficult to ascertain the reason.
The Medicine Saint, observing from the shadows, suddenly noticed something amiss. The Martial Arts Lin Yifan was using seemed mixed with other Martial Arts, appearing similar on the surface but vastly different in reality.
He didn't know if these Martial Arts were Lin Yifan's own insights or acquired from cultivating other Secret Manuals, so further observation was needed to form a conclusion.
Every move of the Immortal Level Martial Arts landing on Zhu Kang's sword made him feel extremely strained.
This power was already equal to his current strength, meaning he might not be able to take down Lin Yifan.
To him, this was a humiliation.
He was at a much higher Realm than Lin Yifan and could also fight beyond his level. If he couldn't take down Lin Yifan, he would surely be laughed at.
