History of Hidden Swarm

The Hidden Swarm is a Hive brood that served Crota, then dominated the Moon; its members were marked by red-orange coloring and nails through their arms and held the Hellmouth. After Shadowkeep it fell under Crota's daughters Hashladûn, Besurith, Kinox and Voshyr, who built the Scarlet Keep. After Osiris defeated them, survivors pledged to Xivu Arath, fighting the Lucent Brood and Guardians.