A flying war machine powered by AI became very widespread during the last Corporate war. Because of their advanced AI with basic emotions and the time spend together with the owner, many veterans view them as some sort of housepet, a very deadly housepet.
In the world of endless war there will always be those who are ready to make money ona bloodshed. They rely on every tool available to them, firearms, ambushes, hacking, and hand-to-hand combat. Mercenaries fight only for profit, so they are unreliable and can flee or change sides if it suits them.