Far Sight Lost
From Halopedia, the Halo wiki
Far Sight Lost was a Covenant destroyer, part of the Combined Fleet of Righteous Purpose. In 2552, it was sent on the mission to Onyx with the Incorruptible's battle group. It was commanded by an Elite Ship Master named Qunu.
When they arrived at Onyx, the Far Sight Lost was sent ahead of the fleet and tried to make contact with the Onyx Sentinels in orbit around the planet. The Sentinels responded by destroying the Far Sight Lost.
