Hmm, MC should know that this particular knight is looking for his owner, that's why he was captured. He should remember that from his last run in and death. Last time he was killed because Rena was assumed to be the owner. This time he wasn't killed because the owner was unknown. That he couldn't piece this mystery together is rather silly. Also how does ripping off his jaw stop him from speaking? The knight seems to have a good amount of skeleton experience if he knows that works.