Invincibility
From Halopedia, the Halo wiki
Invincibility is a piece of equipment featured in Halo 3.
It confers the user with a brief period of invulnerability. When activated the player is covered in shining bands. It is known to be possessed by some or all Brute Chieftains in Halo 3, giving chieftains a brief period of time where they may chase after the player with the Gravity Hammer unhindered, giving them a significant tactical advantage unless you somehow melee them from behind. In campaign, it can be found on some dead Brute chieftains that haven't used a powerup yet.
It is not present in multiplayer.
