Beheading the Human King like this.
King Wu's betrayal of the clan is the same.
Once King Wu betrays the clan, it sets an example for future generations of the Human Race. If even the Human King can betray the clan for his future, how can we not?
Once this mindset appears, those who betray the clan will only increase in number.
Therefore, Jiang Chen wants to prevent this at its root. Once he confirms King Wu has signs of betrayal, he will act immediately.
This is his purpose in coming to the Human Race of the Immortal World, to confirm King Wu's intentions.
"The Human Race gave me life and raised me; I will never betray it."
King Wu first expressed his stance that he will never betray the Human Race.
Hearing this, Jiang Chen couldn't help but nod, though his ideals differ, King Wu ultimately hasn't abandoned the greater good of the Human Race.
But then, King Wu continued, "However, my master has also shown me great kindness, how can I face him with blades drawn?"
"Hmm?"