Battle of Sunaion

The Battle of Sunaion was an engagement fought between the joint forces of the Swords of Sanghelios and the United Nations Space Command and Jul 'Mdama's Covenant faction in 2558.

Prelude
Following the disappearance of MCPO John-117 and subsequent abrupt attacks on several colony worlds, Spartan Jameson Locke was tasked with tracking the rogue Spartan down and returning him to the United Nations Space Command. To that end, Locke met with Arbiter Thel 'Vadam of the Swords of Sanghelios and studied various accounts and recordings of the Master Chief's past endeavors in order to better understand the Spartan's history. A team of SPARTAN-IV supersoldiers under Locke's command subsequently took part in a joint operation with the Swords of Sanghelios against Jul 'Mdama's Covenant faction.

Battle
The Swords of Sanghelios began its assault on the city. Several warships contested the skies above while a force of Lichs and Banshees were deployed to the city. 'Mdama's Covenant, now greatly weakened, succumbed to the vicious fighting and took heavy losses. Promethean constructs soon began to appear. Soon, Fireteam Osiris was inserted into the city and began engaging the Prometheans. As they neared a Guardian, Locke and Osiris encountered the Warden Eternal, who would not allow them access into the Guardian.

List of appearances

 * Halo 5: Guardians