Haka

Haka was a Sangheili of the Covenant Empire that served as a military assistant to the High Prophets during the early years of the alliance.

Duel with Fal 'Chavamee
After the then-current Arbiter, Fal 'Chavamee, was declared a heretic by the Prophets, he sought to supplant Fal and become the head of his clan.

He was led by one of Fal's servants to Fal's wife, Han, and forced the servant to kill her, promising that the clan would be saved by his actions from the wrath of the Covenant. After her death, he killed the servant as well, leaving their bodies as a challenge to Fal to direct combat.

Death
Engaging his opponent after the latter had slaughtered an entire Covenant Army unit, Haka mortally wounded Fal, but was in turn stabbed by an energy sword, both warriors dying at the other's hands.

Trivia

 * Haka's clan name is unknown. Given that he was seeking to take Fal's role as clan leader, it is likely that Haka was a member of the same clan, and thus would become Haka 'Chavamee.
 * While a Sangheili, Haka's style is decidedly Japanese, with his armor resembling that of ancient Samurai warriors. Additionally, rather than an an Energy Sword, Haka carries a more conventional metal blade.