Balius parts were pieces of machinery made by Moebius Corps in order to make repairs to their experimental Archangel the Balius. When General Carolina Davis and two allied commanders raided the facility, they gathered these parts, allowing them to reactivate the Balius and turn it against the facility's hybrids.
Balius parts are an objective of the map Part and Parcel. After collecting 70, the Balius will move toward a Moebius hybrid cell, eventually breaking it and initiating the boss fight. Parts crates and defense bots each drop one part, while xenon generators and sigma engines drop five parts.