Commander Miranda Keyes
From Halopedia, the Halo wiki
Summary
Commander Miranda Keyes is the daughter of Captain Jacob Keyes, and first appears in Halo 2. She is a Commander of the In Amber Clad in the UNSC Navy. She later becomes/turns out to be a Reclaimer, like the Master Chief. She removes the Index from the control room before Installation 05 could be activated. She then asks 343 Guilty Spark about the Halo Installations and he says that the Halos would be put on alert and could be activated from The Ark.
Like Sergeant Johnson and other NPCs of storyline importance, she cannot be hurt by any available means. It is possible to test this out in The Great Journey. By utilizing a glitch involving sticking Plasma Grenades to her, it is possible to push her down to the structure where Tartarus lurks. Despite his best efforts, she is invulnerable to his onslaught.
