Villains whose approximate Character Alignment is "Lawful Neutral", known as the "Judge" alignment. These characters value the law more than right and wrong and follow and enforce it almost blindly. They may be different divisions among Lawful Neutrals based on their motives. An example of this would be formalists, who act out of an obsession with rules. Lawful Neutral aren't always malicious and by essence, these characters are mostly amoral (or even villains by proxy).
Pure Evil villains can never be part of this category, because this is a neutral alignment. Instead, they belong to Lawful Evil category. On the other hand, many of them are considered Anti-Villains.