Honestly, Guo Changcheng was painful to watch throughout, but rewatching, it's very noticeable that he's extra painful at the start. What is this, even!

He really doesn't like having to deal with the Envoy, and doesn't trust his agenda at all. (And why should he?)
Yup! The Envoy is a being from Dixing who operates in a completely different system to him, who has no oversight, and who is given very free licence to use his powers. Zhao Yunlan also has no knowledge of what Dixing prison is like at this point, and has been raised by his Dixing-loathing dad.

Protecting people with all your power is definitely a character-establishing dialogue for Shen Wei, and needs to be at the start so we can figure out wtf is going on with him.