The Big Brother
"The Big Brother" is an AI similar to the lower level boss called "The A.I.", however with much higher stats. He has 3 million health and shields, as well as 30k omicron (DPS). When fighting against the Big Brother it will split into smaller pieces that will continue firing until they are completely destroyed. The main weapons it uses are Railguns, Point Defense lasers, Anti-Fighter Turrets, and Plasma Cannons, which are made from Ogonite and Avorion. While the 2 AI´s are pretty similar when fighting them (except for the better stats of the Brother) one notable difference is that every time a piece falls off the Brother it triggers a torpedo launch. These torpedoes range from direct damage to shields and hull to deactivation your shields entirely.
Fighting strategy
Either using a large-sized capital ship with over 5 million shields and armour, or multiple ships that can be pulled back individually when under too much fire, is necessary. Due to the swarms of torpedoes coming your way, some point defense systems at the front of your ship are a great addition. Fighters and torpedoes however are useless and get destroyed after 50 meters away from your ship. Because of the Brother's long range and Railgun weaponry, trying to put in as much pressure as possible from close range is far more effective than long range combat. Ramming is also very effective as most small parts are destroyed immediately on hit and decrease the Brother's DPS. Downside to this is that you may have to deal with 20+ torpedoes when landing a good hit.
Finding The Big Brother
To find the Big Brother a Maintenance chip is required that is sold by mobile equipment Merchant´s that can either spawn in randomly or get summoned via buying a beacon at the equipment dock of an allied Faction. It is not guaranteed that the mobile equipment Merchant sells the Maintenance chip, try again until he has it. Once activated it will mark a location on the map with a skull. The Big Brother can only spawn in the center of the galaxy and unlike the A.I. it will NOT spawn when doing 10+ jumps in empty sectors.
Drops
All the times I tried fighting The Big Brother it dropped at least the following: 1 Legendary Turret (mostly Ogonite level), 1 Exotic Turret (same regarding level) and some rare turrets (also Ogonite)
Notes
Ramming is highly effective against The Big Brother, but can also deal a great amount of damage to the player, because of the torpedoes being launched (30+ torpedoes doesn't seem to be a problem for the Brother). Due to many Point defenses and Anti-Fighter Turrets, fighters are absolutely not viable and will get killed within seconds. When trying to get to a safe distance to recharge your shields, 20km is the absolute minimum, as it will follow the player and shoot from 19km range; though it will try to come closer. Because of the Railguns, armour is an absolute must have on your ship. The Big Brother will immediately attack the Player and Xsotan alike, however it is highly effective against Xsotan. The Big Brother is clearly an upgraded version of The A.I. which leaves the question open of who placed the Brother inside the center of the Galaxy (100 years before the player gets into the Center) and why it hasn't tried to fight the Guardian, or got destroyed, since it is clearly able to fly around and hunt Xsotan.