Halo 3 invincible Brute, and killed with invincibility enabled

Jul 21, 2013 at 10:11 PM
I started the first mission on Halo 3 with max ammo/grenades and invincibility enabled. When I got to the factory area with the brute with the gravity hammer, I killed every other enemy but I couldn't kill that brute. I used 127 frag, 127 sticky, 127 fire, and 127 spike grenades, and shot it with the AR and brute shot for 25 minutes. Not only did it not die, but it somehow killed me. What exactly is up with this?