C2337 I'm Weak and Strong
It wasn't that Shen Shu didn't want to kill them on the way, it wasn't that he didn't have a chance, but he needed to wait.
He would need a large amount of time to wait and see if any other sect would invite the Sacred Master Crimson Dragon Sect to be their guest.
Shen Shu naturally wouldn't waste so much time waiting.
Furthermore, even if he had to wait for an opportunity, it would be useless