Or you could just use 用心棒 (Yōjinbō) which is used to mean bodyguard/guardian, and was used evocatively in the Kurosawa film of the same name. If you put "My honorable" on the front of this, you end up with a phrase that sounds weird in Japanese.
守護神 means "guardian angel" in Japanese, and you can put an honorific on the front of that without it becoming overly weird 御守護神 or 御守護神様. But this may not suit your needs. Is this for a tattoo?
To guard someone, and to enforce the law are two different things, so to try to include both concepts would end up as a very wordy sentence and could fit into a neat, economical phrase.