Qunu
From Halopedia, the Halo wiki
Qunu was a Covenant Elite and Ship Master of the destroyer Far Sight Lost. His knowledge of the ritual responses from the Fire and Repentance Codecies was unmatched.
In 2552, his ship, which was part of the Combined Fleet of Righteous Purpose, was sent with the Incorruptible to Onyx. Qunu was ordered ahead of the main fleet to try and make contact with the Sentinels. The Sentinels, in turn, destroyed his ship and killing him.
NOTE: It is probable that Qunu had a second half to his name, like most Elites, but it is not known.