[zombie au] when ur.when ur brotherturns into a z.when ur brother turns into a zombie and u spend the next several years of ur childhood braving the most fucked up shit ever so u can find a cure and it gets to the point where ur killing parts of urself just to pick up the pieces of ur brother with shaking, cut up hands and glue him back together but at that point ur just going to end up bringing him back to a world that's not worth living in

i have a desperate need to dump a bunch of my mp100 headcanons in one place so please accept all of these, they’re mostly family headcanons & also trans reigen headcanons -so reigen’s mom had him super young, like, a teenager young -she was around 18 when he was born -it was super hard for a single teen mom but she’s a hell of a lot like her son, which is to say: hardheaded & silver tongued -worked to support them both so reigen was a latchkey kid for a bit but she spent as much time with him as she could & was an Aggressively supportive mom - so when her kid, who she’d thought was a daughter, came to her like ‘mom i’m a boy’ around first grade she was like ALRIGHT TIME TO RESEARCH AS MUCH AS I CAN I GUESS -as a result reigen transitioned super early -he was already able to present how he wanted as a kid & his mom WAS NOT ABOVE YELLING AT ADMINISTRATORS/TEACHERS/ANYONE WHO MISGENDERED HER KID and finding every loophole she could to let her son attend school without being misgendered -however they were pretty fuckin poor when reigen was growing up -and around the time he started puberty his mom & him both knew he needed to get on blockers but he was super guilty about it bc he knew it was a lot of trouble & doctors appointments & stuff -to which his mom was like ‘WELL TOO BAD YOU NEED IT SO WE’RE GETTING IT’ -so he was able to get trans related medical care pretty early & so the only real time he ever spent living life outside his actual gender was like... as a tiny kid -as reigen got older it became pretty much a non-issue and the more pressing issue was that They Were Broke -he started working part time in high school to support his mom - a lot of really weird odd jobs like dog walker and the guy who counts how many people go into and out of stores and secret shopper and god knows what else -because his mom was so young when she had him their relationship is a little parental and a little siblings -like, he supports her emotionally as much as she supports him -sometimes more becasue he feels like he put her through a lot as a child so hes gotta be responsible now -his mom is a hell of a penny pincher & taught him everything he knows about budgeting & couponing etc -however she’s got the worst love life & is kind of a mess & oddly ends up asking her son how the hell to handle most emotional situations -which leads to a lot of people like ‘i... kind of feel like arataka is the parent here’ -mobs parents especially -speaking of: mobs parents had him super late (& then ritsu IMMEDIATELY after) when his mom was like 30 -so reigen’s mom and mob’s parents are about the same age -so they kind of immediately decide upon meeting reigen that he’s their lost third son -he can act parental to mob all he likes but they know the truth: he’s their son & they’ve adopted him -reigens mom wants so bad to be friends with mob’s parents but she intimidates them -in that shes this tiny Very Loud Very Open woman who drinks a lot of wine -what the hell is TMI, everyone needs to know about my date last night -relax, dont be so uptight, have some wine -mobs very normal parents dont know how to handle her -she makes fun of reigen a lot and its mostly affectionate -but sometimes she judges him -like when he quit his office job to open up a spirit agency or whatever??? -arataka, do you know how many people i would have killed to have an office job whle you were growing up -how are you going to pay your bills -what do you mean you’re also paying an employee, are you even paying the rent on your office? -arataka if i need to come to seasoning city and scold you in person i will -don’t test me -(she lives far enough away that reigen only really talks to her on the phone or via email) -its not that often bc both of them are actually pretty busy -as she always has like a hundred boyfriends it seems like -she always dumps them -she’s a heartbreaker -reigen is exhausted w her but also he’s kind of just like her -in that he only really does one night stands & cannot commit to save his life -he’s dumped most eligible bachelors in seasoning city - his mom is also aggressively supportive of her wild ass can’t-date-to-save-his-life gay son - coming out as gay was way harder than coming out as trans (bc he was like 5 when he did that) but his mom just laughed at him & was like “whatever, you do what makes you happy, i am the last person to lecture anyone about their love life” -reigen loves his mom a lot eve if she’s kind of a mess -and vice versa -but also when he meets mobs parents hes like ‘OH MY GOD IS THIS WHAT NORMAL PARENTS ARE LIKE’ ...thats it for now im sorry i had to ramble some

Ohhhh I see those tags. Firefly AU? Bro I'm all ears.

Oh boy~! I hope you like Mob angst, because man did I create a lot of Mob angst! >8D

Mob Psycho 100/Firefly Crossover AU

(This is just a brainstorming thing, not meant to be taken as a finished piece. Even if it is 3.6K words...)

Everyone is five years older than in canon. So Mob’s 19, Ritsu is 18, and Reigen is 33.

Arataka Reigen is the captain of the transport spaceship S&S, or the Spirits and Such. He prefers keeping a low profile after a shady past that he’s since tried to clean up. Has an entire crew under his command, none of whom take him that seriously. He still dads them relentlessly. Teruki is first mate, came on board after Reigen helped him out of a tight spot, is surprisingly good at ordering people to do stuff, isn’t a dick about his powers after the new pilot kicked his ass. Shou is pilot, Serizawa is the medic/cook; both are powerful espers that came on board after Shou convinced Seri to run away with him and hijacked the ship to escape, Reigen subsequently hiring them after finding out Shou was a damn good pilot and that Seri needed like so much therapy. Tome is on communications, who took the job on the condition that she be allowed to attempt making contact with aliens (Reigen doesn’t ask). Mezato is a traveling journalist that pays Reigen to let her stay on board and hunt for news stories, but he suspects she’s just a nosy busybody. Onigawara is a mercenary Reigen hired after one too many scuffles, but now has even more to deal with thanks to the guy’s temper. Musashi is a mechanic with experience in fixing up farm equipment, but can pretty easily extrapolate it to an entire spaceship (Reigen isn’t sure that’s how that works, but hey the ship hasn’t exploded yet). Dimple’s a questionable preacher they picked up after he got run out of town, claims to be a priest but acts like he’s got a god-complex or something (might be an alien brain slug). They’re kind of a disaster, but with Reigen’s people skills, he’s able to avert the worst of it.

They’re given a relatively easy job when they take a young man on board, named Ritsu Kageyama. Also with him is an unusually large suitcase, which he says contains “his entire life”. He just asks to be taken as far from the planet as possible but doesn’t elaborate. Reigen can tell something’s up, but doesn’t have the heart to bother the guy, who is clearly going through some bad shit.

Not a day or two into their voyage, the crew finds out that the government has put out a bounty on Ritsu for stealing their property. Ritsu denies doing anything wrong and they decide to search his luggage for whatever he stole. He flips out at this and tries to stop them, but it’s too late. The large suitcase opens to reveal it holds a stasis chamber containing a sleeping young man. They’re horrified and free the guy, thinking that Ritsu is some kind of human trafficker until he yells at them that he’s trying to save his brother. The sleeping man wakes up then, but something’s clearly wrong with him in how he holds himself like a terrified animal. He seems to realize he’s somewhere unfamiliar and curls up, screaming and crying. Ritsu comes in, covering his brother with his coat and trying to soothe the crying man, now clinging to him desperately. The crew is polite enough to back off and give the two some space.

Soon after, Ritsu and his brother are given a chance to explain what’s going on. Ritsu’s brother is silent this entire time, curled up clutching at Ritsu’s side, staring off into space with glassy eyes, like he’s not there at all. Ritsu starts by telling them that everything he’s done was to save his older brother, Shigeo. All of this has to do with the fact that he is an esper and a particularly powerful one at that. Despite the powers, the two grew up pretty normally until his brother was invited to study at a special Academy for espers. Shigeo took them up on it and left home. At first things seemed normal, the brothers messaging each other regularly. But after a while, Shigeo’s messages started to taper off. The few he did manage to get out were short and often about his exhaustion and the trials he was being put through. Then for a long stretch, Ritsu didn’t hear anything from him. Until he receives a bizarre message from Shigeo’s email, claiming that his brother is dead. For some reason, it’s signed by a “Mob”. It takes Ritsu a while to do some digging, turning up results that made him more and more fearful for Shigeo’s life. So Ritsu left to rescue him, dropping everything to break into the facility and get Shigeo out. By the time he got there, he found his brother already in the stasis chamber. He only had enough time to grab the entire thing before hiding it in the suitcase and fleeing to the spaceport.

Which leads to now. Ritsu knows he doesn’t stand a chance against the S&S crew if they decide to turn them in and has resigned himself to that fate. To everyone’s surprise, Reigen declares that they’ll do no such thing. In fact, everyone’s under orders that they’re to do everything they can to protect the brothers. They’re both victims and Reigen can’t possibly give the abused back to their abusers. They can stay.

The crew is less than pleased at this and start yelling at Reigen until he makes them settle down. Ritsu is distrustful of course, but a quiet whimper from Shigeo gets him to back down. Reigen orders Seri to take the two to larger quarters, while he discusses things with the others. Teru is pretty against the whole thing, knowing they can’t hide the brothers forever. It’s only a matter of time before one of them slips and all of them land in hot water for harboring fugitives. Reigen points out that Ritsu is a fugitive for rescuing his brother from said law, which referred to Shigeo as their “property”. Reigen may be greedy at times, but he’s not heartless. He also doesn’t want to admit that the sight of poor Shigeo struck a nerve in him.

As the Kageyama brothers get settled, there comes the question of what they plan on doing. Ritsu’s plan was to flee to the outer reaches and maybe start a new life there. But with the bounty on him, he’s not sure that’s a workable plan anymore. So Reigen offers them a place on the ship. Any skill set they have would definitely be put to use. Ritsu hesitantly says he’d been studying medicine before upending his life. “Medic,” Reigen declares, “Which would be great, because oh my god Seri just can’t deal with blood.” With a lot of reservation, Ritsu accepts and the job is sealed. As for Shigeo… Reigen decides that he’s infirm and can’t be expected to work yet, much to Ritsu’s relief and zero response from Shigeo.

Things settle down in their own weird way. There’s shenanigans on various planets, Reigen scraping through bad situations through his sweaty charisma, things get shot at, lots of running, like how most of Firefly went.

As time goes on, the crew observes a lot about the two. Ritsu is normal enough, maybe a bit naive in some regards and a bit too aggressive in others. By contrast, Shigeo doesn’t speak at all, doesn’t make eye contact, and is quiet and submissive. He’s a bit perplexing. He always looks haggard, bags under his eyes, hair set in an overgrown bowl-cut pattern. He generally goes around barefoot, preferring oversized knitted turtlenecks and sweaters to hide himself in. He wanders the halls aimlessly, often reaching out to touch the walls. Sometimes he’ll stare at a spot for hours without moving. Other times, he seems to be listening for something only he can hear, sometimes even humming along to some strange tune. They tend to find him curled up in odd places, sometimes observing the others as they go about their duties, sometimes blankly staring into space. The more… interesting times are when Shigeo gets flashbacks of some kind, triggering his powers spiraling out of control. These episodes leave him screaming in the eye of a hurricane of objects until Ritsu can get to him and calm him down. Because of this, Ritsu spends most of his time at his brother’s side, trying to coax him into talking, eating, or calmness. He often glares at anyone who dares approach them. The few times the two are separate, Reigen finds himself gravitating to Shigeo. He talks to the guy, just sharing stories or offering words of encouragement. Shigeo never responds, but Reigen can sense something in him paying attention and keeps it up. Then Shigeo has an episode without Ritsu, leaving Reigen to dive in and calm him down. Something about it works and he’s able to comfort Shigeo until his brother arrives.

Not long after, Reigen finds a lone Shigeo huddled in his bunk of all places. A baffled Reigen asks what he’s doing there, not thinking he’ll actually get a response. “It smells safe,” Shigeo quietly answers. Reigen realizes it’s because of the incense and candles he kept from his old job and goes on to explain when the fact that Shigeo just spoke to him finally hits him. He has no idea what to make of this, but if his bunk smells safe then, sure, Shigeo can stay if he likes. Before dozing off, Shigeo corrects him. “My name is Mob. Shigeo is dead.”

With that bizarre proclamation, Reigen confronts Ritsu about it. However, Ritsu gets mad that Shigeo actually spoke to Reigen of all people. Reigen doesn’t see what the big deal is, but Ritsu tells him that his brother hadn’t said a thing since he was let out. Reigen is left even more confused, as he thought they had been talking. With some more prodding, Ritsu admits that he has no idea how to really take care of his brother, able to tend to physical needs but not mental or emotional ones. Nor does he know just what the Academy did to make Shigeo this way. He knew his brother was autistic, always having trouble socializing and interacting, but it was never like this. Neither did he claim he was dead nor refer to himself as Mob (which is what Reigen refers to him as from then on). (how do i conclude this section i have no idea 0_0;;;)

To Reigen’s surprise, Mob keeps turning up in Reigen’s quarters no matter how well it’s locked. Mob is often found sleeping or blankly staring at the walls. Reigen doesn’t have the heart to kick him out. Though Mob doesn’t say anything, Reigen gets the sense that the young man keeps coming to Reigen’s room to get away from his brother, whose overbearing side has been coming up more often.

Afterwards, the others begin finding Mob in their personal spaces. He seems to particularly resonate with the other espers: Teru finds something grating about his presence, Shou is more fascinated with him and tends to poke and prod at Mob more, while Seri appreciates his quiet, non-judgmental presence.

However the thing that breaks Mob out of his silence is when Claw rears its ugly head. During one of his more lucid moments, Ritsu manages to coax Mob out to explore the spaceport the ship has docked at. Things seem to be going fine until Mob freaks out at the sight of a weird triangle symbol painted on a door. He runs like his life depends on it, quickly losing Ritsu and getting lost in the crowd. Ritsu freaks out of course and enlists the help of the crew to find his brother. It’s Teru who comes across Mob huddled in an alleyway. Mob is shaking, muttering something about Claw searching and finding him. Teru doesn’t have time for this and hauls Mob up to leave, but are stopped by a hooded figure. The figure tells them to come quietly or else things will get ugly fast. Teru has no intention of listening to some thug, but realizes something might be wrong when Mob desperately begs him not go with the figure. It’s because Teru’s guard is up that he’s able to fend off the figure’s sudden very psychically charged attack. The figure turns out to be Koyama, who intends to bring the two psychics in. A fight breaks out with Teru on the offense and Mob on the defense. The fight eventually gets out of hand enough that Shou and Serizawa come in to help. Their arrival is enough to freak Koyama out into fleeing, recognizing the two as powerful espers. (chase down and capture Koyama? give them time to dump him in a jail and leave Claw wondering what’s going on. otherwise he gives their location to base, meaning they get chased) No one’s entirely sure what’s going on until Reigen drags everyone out into a group meeting, deciding it’s finally time for Shou and Serizawa to spill their backstory (he didn’t ask before to be polite).

Like in canon, Shou is fighting back against his father, still Claw’s leader. Only this time, his father knows about it because Shou ran off with his second-in-command, Serizawa, who reluctantly went with Shou because he thought the kid needed protection. Since joining the S&S crew, they’ve been laying low, waiting for a good chance to start making battle preparations. In that time, Serizawa’s realized the error of his ways and is trying to do right by Reigen and Shou. Both of them go on to explain Claw.

In this universe, Claw is sneakier, running in smaller proxy operations but has roots in places like the government already. Their other major asset is the Psychic Academy that Shigeo attended. In the front, the Academy trains and hones a psychic’s abilities. Most people have super weak powers but do genuinely get a lot out of it. Mitsuura enthusiastically runs that part of the operation but honestly has no idea what the darker side of the Academy is up to. The stronger psychics get a completely different story. These are the ones who are made into pawns for Claw to use in their plot to come into power. Otherwise they’re experimented on in a bid to strengthen their abilities to a dangerous degree.

Teru perks up at this, stating he was invited to the Academy once as well, but opted not to. (why? wanted to stay somewhere familiar? wanted to keep hold on his little gang?) Mob just comments that he was smart not to go.

“They do bad things to you.”

With a little prodding, Mob finds the words to explain himself.

Mob insists that he isn’t Shigeo and that the real Shigeo died. That Mob is just a thing inhabiting Shigeo’s body, nothing more. Why he calls himself Mob is because he’s “just a face in a mob, [he’s] no one, a nothing.” He knows a lot about Shigeo, who he was and what he was like. He knew that he was an esper prodigy and the Academy took advantage of that. But they went too far. They put something in him, something that was never meant to be. It killed Shigeo and Mob was born from his shattered remains. Now it’s just the two of them in there, Mob and the Thing. Mob’s been doing his best to keep his distance from the Thing, but it’s hard to do when he’s barely functional. Mob can’t quite explain the Thing either, describing it as a black hole with its own mind trapped in his head.

This is all a bit much to swallow at once, so Reigen breaks them up for now and promises to come back to think of a plan.

Ritsu hasn’t been taking this well, hurt and confused by what his brother is saying. While his brother is obviously not dead, Ritsu’s not sure he can handle losing the person he was. He insists on calling his brother by his real name. Mob can only sigh.

Though their relationship is strained, Ritsu resolves to do everything he can for his brother. Mob tends to shrink away from this. He insists that he’s not Shigeo, therefore: not Ritsu’s brother. But Ritsu is able to get through to him by reasoning that if Mob was formed out of pieces of Shigeo, it means that Shigeo can’t entirely be gone. But this isn’t about that, Ritsu admits. This is about who Mob is. If Mob formed in Shigeo’s body, then that makes it Mob’s body too. And Mob’s body is blood brothers with Ritsu. As far as Ritsu is concerned, Mob IS his brother, whether he likes it or not. Mob isn’t sure how to feel about this until Ritsu hugs him, telling Mob that he isn’t “a nobody, a nothing”, Mob has family and that means he IS something, someONE. Though he tries not to, Mob breaks down crying.

(Presumably, they go in to take care of the Claw problem, possibly first with 7th Div. cell before thwarting the World Domination arc. Blow open giant government secret like in Firefly/Serenity canon? Would probably have to break into Academy again to figure out what they did to Mob, learns about the Thing in detail here. No idea where other elements would go, like Mogami arc. How would space ghosts work? Maybe Mogami arc could be a haunted spaceship story, replace Reavers with evil spirits. Broccoli arc???? HOW DO EITHER STORY END? HOW WOULD THIS END??)

Stuff that would probably only be hinted at in-story, but can be fully explained here:

Mob is either Shigeo gone insane or a new personality entirely. Both are plausible.

The Thing is ???%. While it’s still a mystery in canon apparently just Mob’s powers set to survival mode (something to do with a Japanese idiom?), here ???% is a tiny scrap of what can only be described as a cosmic entity. It’s a small, inky black, strange free-flowing blob, lit up with intermittent glowing white spots. When its discoverers noticed it reacted strongly to espers, it was taken to the Academy to see what it would do. They thought it could be used to give a massive boost to psychic powers. It was implanted in Shigeo to test it out, but his powers went haywire and leveled the building.  When they found him at the epicenter, Shigeo was a shivering, crying wreck. It would be the only thing he could do for a while.

The implantation of the Thing shattered Shigeo’s mind as it forcibly made room for itself in him. The Thing did not originally have a mind of its own. But when Shigeo broke, it absorbed enough pieces of him that it gained self-awareness, changing it from a blob into a shadowy copy of Shigeo. With pieces of humanity in it, the Thing understood human thoughts and emotions. While the Thing could simply have taken over Shigeo’s body completely, it didn’t out of regret for the consciousness that originally was there. Instead, it nudged the bits of Shigeo that were left into a new entity entirely. Sadly not enough was there to create a functioning person, instead the new consciousness was marred with fear and pain. It would come to name itself Mob.

To the Academy scientists, the procedure damaged Shigeo’s cognitive abilities, leaving him unable to recognize his own name or even understand human speech. Instead, he acted almost like a terrified animal half the time. The worst came in the form of screaming episodes, where he seemed to see something terrifying no one else could (it was the Thing manifesting in its vessel’s mind, curious about the entity it shared a body with; it didn’t know what to make of the screaming and crying, so it kept its distance). Only twice did lucidity briefly return: once to ask for pants; the other was to beg them to stop hurting him. The Academy tried many different unsuccessful treatments on him, steadily getting less and less humane until it became more of an exercise in torture than anything else. Ultimately, the Academy deemed Shigeo too unstable to continue making use of, opting to put him in stasis until they could figure out what happened. However, both minds overhear this and in a rare moment of joint lucidity, they secretly send out a message to their brother for help. Afterward, the doctors have to physically fight Shigeo to get him sedated. Shigeo is put into a small stasis chamber and set aside, where he was supposed to sleep indefinitely. It takes a while, but Ritsu is able to break in and is horrified that his brother is in a freaking box. And things go from there.

Mob hates being alive. He doesn’t want to be here. He’s convinced his existence is a mistake, one that he constantly regrets. Most of this pain comes from simple self-hatred, that he’s alive in a body that doesn’t belong to him and never did, that he unfairly stole Shigeo’s life. It’s made worse when Ritsu expects Mob to act like Shigeo but he never can, feeling like he’s incapable of being a real person. There’s a lot of crying on his part, driven by intense despair. It takes time, but Mob slowly stabilizes as he comes to terms with his existence, characterized by increasing moments of speech and lucidity.