Mercenary factions supplement a main faction with hireable units, talents, and additional hero choices.
Each mercenary faction can supplement your main faction in various ways. Mercenary units can be hired periodically over time for hex / flux costs. Factions also provide their own set of unique faction-wide talents, and provide a hero you can choose from (when not playing as Legion)
There are 7 Mercenary factions, 5 of which are currently playable:
Arandi - Advanced aliens with the ability to manipulate space and time.
Cha'Kru Kingdom - Gigantic crabs and their humanoid companions, worshipping gods of the sea.
Free Corsairs - Human space pirates formerly known as the Dread Raiders.
Koru - Sentient plants with a symbiotic relationship with the Grell.
Marran - Isolationist aliens known for long-ranged weapons.
Sanctuary - Robots specializing in healing and buffs.
Valkaru - Warlike alien warriors.