Fal 'Chavamee

Fal 'Chavamee was a Sangheili of the Covenant Empire who served as an Arbiter and clan leader sometime before the Human-Covenant War.

Duel with Harka
'Chavamee believed that the Great Journey was a lie. When he began to openly question his race's new alliance with the Prophets, he was declared a heretic. Harka, a member of Fal's clan, took advantage of the event; in an attempt to provoke and defeat Fal, Harka forced one of Fal's closest friends into killing Fal's wife, Han.

Fal later found the bodies of his wife and friend in his home. He swiftly moved to accept Harka's challenge, literally plowing his way through an entire Covenant Army unit to reach his wife's murderer. When Fal finally meets Harka atop a Forerunner structure, the duel begins. After being mortally wounded by Harka's blade, Fal managed to stab his foe. Both Sangheili died at each other's hands.

Legacy
Before Fal's actions, the rank of Arbiter was considered a privilege. Fal's heresy led to the Prophets declaring the rank of Arbiter to be one without honor, given to those who could be useful to them as a last chance to regain their lost honor before death.

Trivia

 * Fal wears a unique Arbiter helmet that has immobile mandible guards set into the helmet piece itself and enclosing his whole head. The left half of this helmet was cut off during his fight with the Mgalekgolo.
 * Strangely, on the Halo: Legends DVD disc, subtitles show this Arbiter's name as being "Thel." Whether this is his actual name, and is just pronounced as "Fal", or just a mistake is unknown.