The Brute Bodyguard is a Brute (Jiralhanae) rank/specialty [1]. They are responsible for the protection of their tribe's Chieftain, they are also responsible for the enforcement of tribal law. Whenever there is a Chieftain nearby, you will encounter Brute Bodyguards which look very similar to Captain Ultras. Bodyguard Brutes are also seen to be protecting Truth on the level The Covenant. They are likely the replacement for the Honor Guard being that Tartarus also had Honor Guard protection.