From Halopedia, the Halo wiki
Swarmlord is a Mgalekgolo title for elders who lead swarms of Lekgolo. Few Swarmlords appear in different Covenant remnants, notably Colony of the Banished, and Warzone simulations depicted them in Jul 'Mdama's Covenant. Swarmlords encountered in War Games include Magsanggalang, Magtanggol, Makipagtunggali and Nakagagalit. Unlike other Mgalekgolo, Swarmlords typically don Ultra-class armor resembling those of Evocati with blue glowing lights and strips. Swarmlords appear as mythic bosses in Warzone simulations.
List of appearances