Wikia

This challenging Co-Op Mission takes place deep beneath the planetary surface at a Rift Mine known as the Maw of Despair, the most dangerous Rift Mine on the planet Dust and home to the oldest Outcast Tribe - the Shade Warriors. With each Shade Warrior having a heart of pure Rift Energy along with enhanced Toughness and Combat Skill, players will experience fire-fights in the Maw of Despair Co-Op Mission that will be the true test of their shooter skill.
http://starhawkthegame.com/preorder/?CMP=StarhawkBeta-GOOGSEM

Maw of Despair Outcast Pack