For Xiao Wu's desire, Wu Youyou did not refuse. After all, she didn't mind if this move was learned by others, as it relied on the will of the heart, and the boxing technique was just "an external thing."
But the practice of spiritual boxing intent is very difficult to teach. It requires someone to have an emotional stimulus, otherwise it's like a rootless duckweed—no matter how you teach it, it can't be learned.
And the personality of this guy Xiao Wu is "carefree," so what could move her?
Even in other dimensions, the moment when Xiao Wu was most touched spiritually was when she sacrificed herself for Tang San... Wu Youyou believed that if Xiao Wu could crystallize the "protection" and "love" she had when sacrificing herself in other dimensions, she might achieve something.
But the current Xiao Wu simply couldn't do it.
Not to mention that Tang San was already dead.
