From Halopedia, the Halo wiki
A kai'd was a military unit of the Covenant, comparable to the human military company crossed with a pack of bloodthirsty warriors. Personnel assigned to a kai'd were outfitted with their own unique armor and utilized a separated battle network for communications.
During the Ninth Age of Reclamation, upon learning that the United Nations Space Command intended to deploy Spartan-IIs to destroy his Fleet of Inexorable Obedience over Biko, Fleetmaster Nizat 'Kvarosee ordered First Blade Tel 'Szatulai to assemble a kai'd composed of the fleet's best warriors to hunt down the Spartans. 'Szatulai assembled the Bloodstars kai'd, a flotilla composed of intrusion corvettes and skilled warriors. However, most of the kai'd was destroyed during a battle at Zhoist.
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