When they saw the Three Devils of Han and saw their capabilities they know how hard this task would be for them.
The Three Devils of Han look at the guest that have come to the mountain.
They did not care about these people but they care about the gaze of that Sword Immortal in the hut.
They could feel his gaze on them.
The Crippled Devil Han Xiao was taught a powerful movement technique by the Sword Immortal which is why he could imitate those speed akin of a grandmaster level
He himself did not reach that level yet but because of the lightness technique he was imparted by the Sword Immortal, he looks like he could run away from a grandmaster even if he met one.
And he is confident that if he trained this technique, his speed would improve and if he does meet a grandmaster level martial artist when he travels the Jianghu, he is confident he could outrun them