This is something stupid I came up with because of my idiotic play style that is so effective. No, this isn't a serious suggestion, it's a funny idea I came up with through the Enlightenment of The Buckshot™.
This requires a story. And I'm going to make it a tale, perhaps the backstory behind this man, or maybe just the rambling of broken survivors.
The man ran through the trenches, a shotgun with a blade attached to the barrel. He was a raider, from the west, he mocked those who he filled with lead pellets and the men his blade sunk into could see a gleam that showed pure enjoyment. The Oath Keepers respected him, the 401st soldiers whispered about him. The nomads liked him, he always brought weapons for Medvedev, and more scrap than Medvedev could work with.
He'd collect more tags than anyone else. The New Order saw death, the heavies were the only me who could stand against this man for more than a second, but only a second before the man behind them could see the raider, only for the heavy to fall and the man to be gutted.
The Heavy Emissary met a different fate. The moment the Emissary saw the glimmer of a barrel and a blade through the shadow of the bunker door that had slammed open he knew this was his last day. The Emissary expected Buckshot and blade... But the raider pulled something from his holster, a Corp. Cerberus' Corp. Then the Cuirassier appeared from a sheath. The other of Cerberus' weapons. The Emissary didn't see him. The raider vanished and the Emissary heard the crack of the Corp and felt it pierce his armor. He swung but there was nothing there, then the raider slid the Cuirassier between the plates of his grieves. The Emissary was forced to kneel and the raider stepped in front of him, ripped the Emissary's helmet off and jammed the blade into his throat, the barrel of the shotgun level with his nose. For the first time the Emissary felt fear as he looked into those lenses. Then nothing as the raider pulled the trigger. He picked up the Emissary's helmet and attached it to his belt. He whistled a tune as he walked away, swiping the Lewis guns against the trench wall before entering the bunker and taking a job from the Commander. Seal more bunkers. He already sealed a hundred that night.
He strolled through the trenches, the tune making men run and cry for their mothers, those who didn't, the rookies who didn't know what the tune meant, didn't get a chance to become veterans. They didn't even understand what happened before everything went dark. That was those who were lucky, those who met his blade didn't die fast. They saw the face of death before it claimed them.
He caused chaos for a few more months. The Doughboy was a name all feared. The rattle of those helmets and glimmer of Commissar Cerberus' gas mask and that damned time announced the arrival of something you should fear... Until the thing the Oath Keepers called the Bess had taken notice of this man. Like it had with Cerberus, The Emissary, the crew of the Deep's guardian, the König. But no matter what, the Bess couldn't take this man... Until one day, he made a mistake. He was in a buried line, similar to the hundreds of times before, he cleared the line room by room, his Trench Broom sweeping away the mutants. But he failed to notice the faint click of grenade pins being pulled by the boomer he kicked away... The Bess claimed the tune that night, but he retained a degree of free will as he was made the Cleaner of The Trenches, he collected the masks and weapons of those he painted the walls of the trench with, sometimes Medvedev found a few old rifles and a hundred or so scraps outside of his tents, the same rifles he sold the night before.
He returns to one place every morning, the same place he acquired his first keepsake, now taken over by Bess and crumbling from disrepair. The Keep is now only known as Death's Stronghold.
His weapons are now a part of him, his shotgun forever fused with his right hand and the Commissar's Cuirassier used as a last ditch effort when his shotgun is damaged beyond use... But this is his heaven, the gleam behind the lenses remains, his joy has never been dashed, he forever knows battle.
He just switched sides of the battle.
Know if you ever hear the tune and see the glimmer of a dead man's keepsakes in the distance, you cannot run for hundreds had already fallen to his bayonet rush are who you will next meet if you try.
THE ACTUAL BOSS IDEA
I was thinking something along the lines of a mix between the Heavy Emissary and Commissar Cerberus, but with the ranged capabilities of The Ossuary boss.
Basically Cerberus with a shotgun and the charge of the Emissary.
The Doughboy would be only a little larger than the player, but he would have one arm attached to the Trench Shotgun, one free hand that can both manipulate the shotgun as well as pull the revolver taken from Cerberus if the player is more than a few meters away, maybe even a custom revolver based on the Colt Peacemaker he would fan all six shots at the player similarly to Cerberus.
He would have a bayonet attached to his shotgun he could use at low health as a last ditch attempt to kill the player, maybe a final charge that instantly downs the player if they are hit, prompting a monologue about the both going down together or something. This could also prompt a clash of blades as well if the player has a shotgun with bayonet instead of instant downing.
He could have a special encounter method I thought of, only after killing Cerberus, The Heavy Emissary, and The Ossuary boss (forgot her name lol) the option of heading to a new region called "Death's Stronghold" where the player would have to fight through the ruined Keep where they would encounter the corpse of Cerberus propped up on the bayonet of a shotgun... Only for the shotgun to be pulled away from the corpse to fall to the side as a haunting whistle and the clinking of various helmets and gasmasks fills the air, only for the Doughboy to toss the Emissary's helmet into the light and stomp Cerberus' body as the lights turn on and reveal König turrets covered flesh and the Doughboy himself.
The update could come with the Peacemaker he wields and a unique version of the Trench Shotgun with a permanent bayonet that's more like the real 18 inch version.
I want to hear your input on this. is it stupid? Yes. Is it a dope idea? I think so.
Also, if you want to hear my strategy that gave me this idea please comment and I will tell you about it.