I just had my own Theory on what Knox's 5th Commandment is, lol.
Since in the Ep5 Arc, the actual use of the Knox's 5th was not not used.
ElderKain's Knox's 5th: The culprit cannot be of supernatural origin.
If the above is the case, it was purposely left out becasue if that was know, it would be instant win for Battler, and if that is the case as well, it works well with actual mysteries, like the "
Hound of the Baskervilles" story on how it wasn't really a demon hound (
supernatural creature) but just some trick from the culprit.
or like Scooby Doo Mysteries, lol.
If you take my Knox's 5th into consideration, it fits well with the other commandments.