The difficulty of controlling one person's Internal Breath was naturally worlds apart from controlling the Internal Breath of four people at the same time.
If not for his previous experience, Chu Nan would definitely not dare to have such a bold or even arrogant thought, let alone truly use it.
Now that he had tried to mobilize the four of them' Internal Breaths to use the first level of the Nine Revolutions Cultivation Technique to enter the Second Revolution, Chu Nan immediately felt a huge pressure.
Be it the powerful burden that his Internal Breath brought to his body, even his A.I.-like brain felt a trace of pressure because of such an overly complicated situation.