History
The Blackstar Legion's origins run deep. Claiming to have founded in 2075 by former agents of Pinkerton Consulting Inc., the Legion began as 'Bowie Consulting and Investigation' during the tumultuous Third World War on Earth. What records exist of their pre-spaceflight days have been edited, substantially, by the organization themselves. What can be dug up ties them with private military actions taken within the former United States of America, including one notable incident in 2092, whereupon a spaceport had been commandeered, and it's staff members shot, to stop a shipment heading to Mars. They've adopted new names with the passing of the centuries, before eventually becoming Blackstar Consulting in 2275. Then, in 2276, the company violently collapsed; the cause of which is unknown, but the end result was the splitting of the company into two halves: 'Bowie Logistics' were the ones who 'went legit', as often claimed. The remainder would become the Blackstar Marauders.
Blackstar Marauders
Existing on the fringes of Orion space, the Marauders were a barely-legal band of mercenaries, investigators, and military veterans. Their mission statement was simple: they were loyal unless the check bounced, and their methods were as discrete as necessary (read: depending on how much you offered). Taking to the crumbling frontier of civilized space, the Marauders were instrumental in the ensuing rise of megacorporate power. Channeling their old roots, Blackstar would often be hired to break up labor unions, take over mining colonies, or sabotage cargo vessels: anything was fair in the times before the establishment of the Galactic Trade Committee, and OriCon's reach far exceeded it's grasp. The Marauders slowly grew over time, forming disparate bands of ships that only 'claimed' to be mercenaries; one could charitably say that they were an organization of pirates, thieves, and terrorists. The near-constant growth and sinking reputation led to losses over time; by the late 2400's, the Blackstar Marauders were little more than a footnote in the frontier, as many of it's constituents broke away to form their own, more honestly titled, pirate warbands.
Their luck would change soon, though; just when the Marauders were nearly dissolved, the Syndicate Wars began. The frontier of space was engulfed in corporate warfare between NanoTrasen and it's rival corporations. The Marauders were quick to offer their services early in the war, and NanoTrasen, seeing much of their resources get destroyed every passing week, agreed. The Marauders were legitimized as a corporate subsidiary of NanoTrasen, and set out to do what was asked of them. For the next one-hundred years, the Marauders were supplied well, and were instrumental in stopping Syndicate actions in the frontier that would've led to untold amounts of destruction. Unfortunately, their methods hadn't developed much since their pirate days: NanoTrasen's protection was the only reason why the Marauders weren't arrested by the Orion Confederation on warcrime charges, especially the Burning of Sif in 2541, the Halifax Rebellion in 2544, and the Yandax Culling in 2550.
Modern Day
Shortly after the Syndicate Wars ended, the Blackstar Marauders would end their contract, formally renaming themselves the Blackstar Legion. With their fleet of NT-backed spaceships, they've established a powerful stranglehold in the mercenary market; a grim sign indeed, where even blood money could be corporatized. Operating out of their main fleet, the B.L. Ares Rising is the Legion's center of operations. From here, the Legion's ships and officers are coordinated, equipment and cargo is shuttled to and fro, and an entire deck has been given over to logistics and payments.
Ethos
If their history did not tell you as much, the Blackstar Legion is a massive mercenary company. By their very nature, ethos is of no concern: only payment. There may be noble souls who command Blackstar ships, willing to work for the lowest bidder if they can tell they're struggling, but are far outweighed by the company standard. For the vast majority of Blackstar 'employees', there is only one statement that matters in the galaxy: 'Fuck You, Got Mine.
Influence
The Legion has had no visible hand in the frontier's affairs, which is just how they like it. They have nowhere near the power of the megacorporations in the frontier, and the heating tensions between OriCon and the Hegemony are as concerning as they are enticing to them. They still send out recruitment ads through the exonet, even hacking billboard displays to advertise their services to an unsuspecting public. NanoTrasen, by policy, polices exonet traffic to remove these adverts from their systems. And in the event that physical posters appear, they're to be shredded immediately, with video footage of the poster's destruction.