Lee Chang is definitely also into those questions, and I think he would probably let these guys do most of the talking. (Like having Mu-yeong ask all the questions while he puzzles it together. )

He would also suggest the questions such as:
Why is he gaining power / support now? Did something new happen? even though he's pretty sure he knows the answer to it, and Why the arm thing because he thinks it's symbolism but hey might have some other actual reason.

Depending on how the previous questions go and if he's recognized he may straight up ask So how would one be able to meet him...