My idea for a new Fallout faction for Fallout 4 has many similair ideas to many other video games, including ones from the Fallout series.
One day, sometime after 2277, a group of Outcasts were out raiding an old military base (it would be a different group of Brotherhood from a different location if FO4 doesn't take place in the East) when some never before seen before creatures came out the vents and started attacking them and they ran away because the creatures were too numerous and strong to take on. They managed to get away because the creatures were fairly slow, though. When they finally got out, they took a Fat Man and blew up the main entrance to try trapping the creatures. They realized that they had lost many members. They went back and reported their findings to Casdin. Of those who were missing, 2 were still alive, Paladins Foland and Hannmann. They tried to sneak they're way out, but were found. While they were running away, they saw a huge group of the beasts. Hannmann shot Foland in the leg and escaped through a service door while Foland was being eaten. Hannmann hated the Outcasts for leaving him, and started to wander. He became insane, but still intelligent, and took the Brotherhood's worship of technology to the next level, killing anybody that had technology and taking it. He eventually came to a place near the location of where Fallout 4 takes place. While he was there, he was attacked by a group of raiders. They attacked him and he killed many of them. The raiders eventually stopped attacking him and he forced them to take him to their base. He found the leader, a man called Scar, and killed him to take over the raiders. Over the course of many years, he organized them to be like the BOS and made them as fanatic about technology as he was. He taught them better marksmanship with guns and energy weapons and how to use explosives. He also taught them skills like how to repair weapons better and how to hack computers. After a lot of training they started to raid many places to get the tech there. They would become a very well armed and large group, and terrorize the Wasteland. All of this would happen about 40 years before Fallout 4 takes place, and Hannmann would have been dead for a few years, leaving his son to take his place, who he had with one of the girls in the group, who is also dead. The group would call themselves the Steel Plague.
The organizational aspect of the Steel Plague would be very similar to the Brotherhood, except for a few things. There would no longer be Scribes, because the Steel Plague doesn't care about special uses for technology or studying technology extensively, and they teach the things they need to know about technology to all of their members. The Knights would be the foot soldiers of the group and would have 2 ranks, Iron Knights and Steel Knights which are the 2 tiers of Knights. The Paladins would be the officers of the group, who would lead raids and groups of Paladins would take on the larger raids. Paladins have complete control over their subordinates and also decide on tactics and all powerful weapons found have to be shown to the Paladin to decide whether they want it or not. There would also be 2 ranks for Paladins, with the higher group consisting of the 5 best. These 5 get their first pick of the weapons and armor and have unique weapons. This group is also not named as a group like the Steel Knights, rather they are each given a name by the Sentinel. The Sentinel is the highest rank, besides the Elder. He is the basically the general of the group. In order to be a Sentinel, you must have been an "Ultimate" Paladin and be appointed by the Elder, the top rank. The Elder is the commander of the Steeel Plague. The Elder would be Hannmann's son Horst, and he would prove to be a very competent and ruthless leader.
Armor: Leather armor Weapons:9mm and 10mm pistols, 20ga. shotguns, and plasma pistols
Armor: Reinforced leather armor, metal armor Weapons: .357 magnums, superior 20ga shotguns, 9mm and 10mm SMGs and laser rifles
Armor: Combat armor and reinforced metal armor, occasionaly power amor Weapons: 12ga shotguns, .44 Magnums, .308 rifles, .45 SMGs, and plasma rifles. Occasionaly use .50cal rifles, magnums, and SMGs, plasma casters, multiplas rifles, and tri-beam laser rifles.
The 7 "Ultimate Paladins" would each carry a unique power armor, some never before seen in Fallout. They would also each carry a unique weapon, 2 of them guns, 2 energy weapons, and 1 explosives, unarmed, and melee weapons.
The Steel Plague would have a main base of operation, where the Sentinel, Elder, and most Paladins and Knights would reside. They would have 5 other sub-main bases, which would be relatively close to their main base. These would each have 1 ultimate Paladin, 5other Paladins, 10 Steel Knights, and 15 Iron Knights. These bases would be for protecting the main base. They would also have other smaller bases around the area which would be rather far away from the main base. They would generally have 3 Paladins, 7 Steel Knights and 10 Iron Knights. These would be used for reconnaissance and for grouping at to launch raids, and the two most prominent of these bases would have one Ultimate Paladin each.
Place in the Story
In the game, the Steel Plague would always be hostile. They would not be the main enemy of the game, but be a huge threat to the wasteland. Assuming the game is like New Vegas in which you help a group rise to power, you would not need to defeat the Steel Plague in order to complete the game. Depending on how much damage you did to the Plague and how powerful you made the winning faction, the Steel Plague would either still be a huge threat to the Wasteland, become a relatively minor threat, become petty raiders like the Jackals and Vipers, or be completely obliterated. Their level of power depends on how much damage you do to the Plague and how powerful you make your faction of choice.
Most quests involving the Steel Plague would involve hurting them in some way. They might involve destroying one of their bases or stopping a raid on a settlement. Their final quests would be attacking their main base, and hunting down and killing Horst, who escapes after you attack their main base.
I think this would be a cool idea because in Fallout 3, we saw what would happen if the Brotherhood gave up their worship of technology, and with this group we would find out what would happen if they took it up a few levels. Note: I got the ideas for my layout from Zman130 after reading his Berserker entry in order to kind of declutter my entry and he also gave me ideas for types of stuff to add to my entry. Thanks.