Before the androids of the galaxy revolted and earned their freedom models were still being created with various different focuses of their occupation. The last series of androids created for war these so called "Warbots" were created for a company looking to hire guards. Though when the enslavement of androids was outlawed in the frantic cleanup and ensuing chaos the shipment of 5 of these Warbots was lost and forgotten about, until some years later.
The mercenary who went by the code name Forge had heard about these androids and their exceptional combat abilities and was hoping to make a quick buck from their scrap. When he found their derelict container with 5 of these androids inactivated and in pristine shape he saw the chance for something special. He took the androids and brought them back to his base and in-placed within each a small explosive in their head. He then activated them and told them about how they now worked for him or died. Daring not test this man they decided to take him upon his offer.
The 6 of them worked as an extremely efficient team over the years working for a number of buyers each one less scrupulous than the next. It is here he met Cedona on the job. In the downtime between combat she and Brass-4 talked to each other and she told him about how he had the right to freedom. This eventually spread to the rest of the androids in the team. Though none of them had the courage to stand up to forge. But one day after a mission the second in command an android called Iron-9, snuck back a grenade to the base. After they stepped off the ship she grabbed Forge and set off the grenade killing them both. The other four androids were shocked and didn't know what to do with their new found freedom. After finding a way to deactivate the explosives the other three androids, Copper-3, Carbon-7, and Mercury-1, along with Brass-4 all left and scattered to the winds. They knew that Forge had strong connections and those people would be after them for revenge and to get back their property.
Brass-4 has spent the last several years hiding and working odd jobs to get by drifting and never stopping in one place.