Cleon
Legend
That wording is fine with me.
Well, maybe CR+1 for a "physical" critter. Not sure about the "mental" type.
Well a wizard or sorcerer that becomes a Phlegamor's Servant would be a lot less of a threat, since it'd lose all its spells. It'd presumably even lose its familiar too. And most of the "wizardly" magical items it had would also become useless.