Chapter 685 tells you all that Su was cool for Su.

He trusted Master Su so much, but Master Su gave him such a serious blow.

Kill people!

He's been with him for seventy years! Seventy years!

Even a dog has enough feelings, but how did the old man treat him? Because he was caught by the depressed and indifferent people, he thought he was a threat, so he had to do everything he could to get rid of him. For seventy years, he has blocked so many shots and arrows for the sake of Su's birth and death and for the sake of the old man. Isn't that enough...