From Halopedia, the Halo wiki
Vicious and cunning warmaster of the Banished.
Leader and creator of the Banished, Atriox is a fearsome warrior who rose to power through his fierce tenacity and shrewd strategic planning honed during the Human-Covenant conflict.
Atriox holds an extremely pragmatic view of warfare and understands the importance of supporting infrastructures and how to build armies and structures cheaply and efficiently.
His charisma and the fervor of his followers make it possible for Atriox to deploy both savage Brutes and Elite mercenaries simultaneously, whereas other leaders would struggle to control such bitter rivals on the battlefield.