I know we all eat up how fucked in the head all the variants are and how shitty/toxic they treat you while still loving you (each in their own weird way) but what if just every single variant treated you in the nicest most loving way possible.
Like you’re the ONLY one who gets gentle touches and kind words. Yeah, some Marks are more gruff and cold than others but there’s literally only love on that mf’s face when he looks at you
They’re all obvs still crazy as hell and would do literally anything for you and to have you but they’re not gonna be unnecessarily cruel or mean (to you!!)
They’re all doing their thing of destroying and killing and RUN to you the second they find you. the switch is immediate it’s scary they’re like needy cats who hate competition bc well. How could they NOT fight over you?? While they’re causing mayhem and basically playing keep away with you, they’re all talking about their own versions of you and keeping you safe from each other.
Legit screaming at each other only to just look at you and start saying the most sappy bullshit
They never hold you too tight!! Never too forceful!! No threats towards you ever!! Just a lot of sad puppy dog looks if they try and be affectionate and you swerve that shit lol
Won’t stop them from kidnapping you tho LMAOO they just love you so much <3 they’re gonna be controlling at most unfortunately!!
Idk if this makes sense I’m high and just thinking about every Mark being nice to me bc I love them
Warnings: angst, blood, hurt/comfort, enemies to lovers, not proofread
A/N: don't worry, this is not over yet! and sorry to all the og Mark fans lmao
[A few minutes earlier, Pentagon Medical Ward]
"So you left my friend alone with this freak the whole time?!"
Cecil's thumb was hesitating on the trigger for the high-frequency device, not wanting to stain his relationship with the original Mark any further - but after witnessing what his variants were capable of, he's certainly not taking any chances.
"Calm. Down." he urges the young Viltrumite while trying to remain amenable at the same time. "We needed to take care of the active threats beforehand, and also...he seemed quite fond of your friend." That last part he regretted immediately after saying it aloud.
"You can't be serious!" Mark now screamed, dramatically throwing his hands in the air, thus making all nearby agents cower in fear. "It was you who told me that one of those psychos tried to lure my mom out to kill her! What else do you think this is? He made my friend believe he's me, to play some sort of wicked game!"
All that had happened those past few days...the death and destruction...Mark blamed himself for all of it, because at the bottom line everything was inevitably caused by his own lack of resolve.
And there he was, hiding away at Eve's sickbed like a stubborn child, cowardly refusing to take responsibility as earth's last hope, while others were risking their lives to correct his errors, hell, while his brother and mom were still out there!
Once again he let everyone down.
But Mark won't let any more people he cares about suffer because of his own shortcomings. This time he won't hold back...
...he'll kill this variant and make him pay for what he's done.
Picking up his mask from the counter, he bids his still comatose girlfriend one last look, very well aware how disappointed she'd be at his latest decisions. She'd want him to go. So he mutters a silent apology before rushing into the hallway, with Cecil following closely behind.
"Teleport me to them. And you better send as many backup reanimen as you can."
[Current time]
"Careful Mark. If our observations are correct, this one is way stronger than the others." The hero huffs in annoyance upon hearing Cecil's voice from his earpiece, watching his other self come out of the debris with not a hair out of place.
Well, most of the variants probably never faced any real threat or even slight disadvantage in their lives. There was simply no reason for them to train properly, since the powergap between Viltrumites and any other species was just so ridiculously high.
This version of Mark however spent his entire life preparing his vengeance on Omni-man for taking the one and only thing he truly cared about...
...and his hard work seemed to bear fruit, since a single counterattack of his was painful enough to temporarily stun the original. He seized the opportunity to pin his opponent down, landing one severe blow after another until both of them were completely covered in the original Mark's blood.
"NO!" you screamed at the top of your lungs, having thrown yourself onto the variant's back as you - brave yet very foolishly - tried to to get those two behemoths away from each other. And in the end, your struggle and pleas actually made the variant stop in his tracks. "Please...don't kill him."
For a split second you see the look of heartbreak and betrayal in the man's face, since seeing you still care so much for the original erased all hope he had started to harbor.
Your world's Mark has everything he ever wanted, and he doesn't even understand how lucky he is.
This is so fucking unfair, it's driving him insane.
The Viltrumite raises his bloodied knuckles to his temples, his jealousy spiraling into a violent, irrational urge to tear the original apart and take his place.
And yet he tries to keep it together for your sake as he couldn't bear to cause you any more sorrow. He glares you down with so much malice "That was self-defense" he scoffed through strained breaths, desperately trying to prevent himself from having a mental breakdown. "I wasn't actually going to-"
Now it was the original Mark's chance to turn the battle around, grabbing the variant by the throat as he crushed him against a mountain not far from the hill you were on.
While your former friend was completely disregarding you, rationality overthrown by his wrath, the other Invincible's eyes were practically glued to you in concern for your safety. At first he was holding back, letting the attacker use him as a punching bag in hopes it'd calm him down...
...but when he recognized the capsules transporting reanimen falling from the sky, he pounced on you with no forethought, shielding you from the impact with his own body.
"Shit, are you oka-" Another time he was torn away from you, with Mark yelling at him to keep his filthy hands off of you. And yet with every move, no matter what, the other Mark did a way better job to prevent any harm than the one who came to 'save' you from that very same man.
"Dude, that's exactly why we cannot fight here!" the variant reprimanded his counterpart while severing the head and limbs from several cyborgs. "Think about your partner's safety! We both only want what's best for them, right?"
"Huh?" The original Mark gave a puzzled look at that statement, the word 'partner' obviously made him think of Eve, but his eyes briefly flickered towards you. "What's that supposed to mea- ah, whatever."
In any other context you would've probably been so embarassed that you wished for the earth to swallow you whole - but this is neither about you, nor was it the time for this kind of talk. And luckily, Mark didn't overthink the variant's words but focused on the truth in them instead, swiftly throwing you over his shoulder to bring you away, so that they could continue their battle without endangering you.
"Let. Me. Go!" You repeatedly punch against Mark's back, horrified to see your newfound friend down below trying to stand his ground against the reanimen. "Tell them to stop! None of this is necessary!"
"Hey, it's me!" Mark tries to soothe you, convinced that you're just overwhelmed by today's events. "The real me, okay? Stop being so irrational!"
"Yeah, I know that, you blockhead!" you blurt out in anger, "And you're one to talk! You let your emotions dictate your actions, as always! I thought Invincible spares the bad guys and tries to talk it out?"
"...not anymore. We all saw today how that way of dealing with villains turns out." Letting you down so far away that you can't even see how the variant is holding up anymore, Mark is about to leave and finish the job when you manage to get a hold of his wrist. "Wait. Listen to me, that Mark is not entirely evil!"
"Are you fucking kidding me?" So not only did you know it was a variant, but now you're also defending him?! "The trauma messed with your head or something. Let Cecil's people pick you up and check on you."
"Seriously, Mark." He finally turned around to take a proper look at you, grinding his teeth as he recognized that naive, caring attitude of yours that always had a positive influence on him in the past. It made his heart swell with both admiration and envy...
...because why the hell were you advocating for a malicious version of himself, especially after throwing away your friendship over something he had no control over?!
"You know this guy one fucking day and suddenly you're on his side?" the hurt in his voice was so tremendous, you felt as if the guilt of it swallowed you whole. "You were supposed to be my friend, and he's the one who participated in making mine and many other's lives a living hell! So why?!"
"...it would be a waste to kill off a potential ally of this strenght, would it not?" Your reasoning got accentuated by the sound of metal and flesh clashing in the background, and you secretly hoped the variant was doing okay. "Maybe he can be rehabilitated."
"God, you sound like Cecil...but even he draws a line at some point. This guy is irredeemable!" Mark ran a hand through his hair, pacing around in circles to clear his head - and yet it was like your role in all this was the one drop that made the pot boil over. "He needs to be stopped! You've seen it yourself, he leveled several cities to the ground and killed a great amount of heroes! Shit, he's caused millions of deaths, do you have any idea what that means?!"
There was nothing to add to this. He was right, about absolutely everything. And yet...
"He-he needed to fullfill his part of the bargain, or Angstrom would've-" A loud bang echoed through the air as Mark's fists met the ground in frustration, effectively cutting you off. "Fuck, do you even hear yourself?! He always had a choice to join the fight on the right side instead of wasting his time chasing after yo-" There was a gleam of epiphany in his eyes that made you a little anxious whether he had picked up on the hints.
"Look, I'm not trying to justify his actions." You pry one of Mark's fists open, intertwining your fingers with his. "But we need him..."
"...we, or you?" That question caught you off guard, but when you wanted to stumble away but Mark pulled you right back. "What he talked about earlier...are we a couple in that other dimension?"
Sometimes you tend to forget that he isn't as dull as he comes across. Damn it.
"I-I-I....it's more complicated than that. I...died in his world." You shouldn't even be arguing about something so pointless right now, and you also don't want to burden him any further, but he keeps prying.
"So what, you want to become the moral support of a mass murderer?" Worded like this it does sound pretty awful. "I know you cut me out of your life, but I still care about you. No way I'm gonna let that happen. It's too dangerous."
Those feelings you harbored over the past decade were like a chain weighting heavy around your heart - but instead of communicating like an adult, you dwelled in self-pity and pushed your friend away. And as crazy as it sounds, over time you convinced yourself there's no way out of this, nothing else awaiting you...
...that was until you met the other Mark, however.
No better timing to free yourself than now, you thought, but Mark connected the dots faster than you were able to confess. "...why did you never say anything?"
"Oh c'mon, you've been doting on Eve since highschool." Mark was not the person to back out of a friendship like this, even if though he didn't reciprocate. If you had told him he'd certainly would've found a way to make this work, since he didn't want to lose you. And yet you didn't want to give the two of you the chance to overcome this, rather choosing to hurt him before you get hurt.
What a stupid, selfish teenager you were back then...
"Now it all makes sense" he speaks to himself, shyly glancing over to you again as he covers his blushing cheeks with his hands. "Fuck, I'm such an idiot..."
"Nonsense, I'm the ass for ruining our friendship over a silly crush." That was the understatement of the year - you were head over heels for this man.
He seems almost melancholic thinking back to all the moments he should've noticed what's going on. All this time wasted going no-contact when you could've worked things out instead...but it takes two to do that, and he's certainly not the one to blame.
Turning his head towards the noise of the ongoing fight, he shakes his head in disbelief. "This is so fucked up..."
"Tell me about it" you chuckle, playfully poking his side in an attempt to lighten the mood, and both of you give each other an appreciative smile. "But we shouldn't make rushed decisions in our current state, right?"
Mark lets out a shuddered sigh, realizing just what kind of hole your absence has tore in his life. But you'll manage to get back to how things were between you. This was a ray of hope cutting through the storm he's been caught into, ever since becoming a superhero.
"God, you have no idea how much I've missed you..."
There's no more time to waste, everything else has to wait until much later. Mark brings you back with him, a safe distance away from where the variant was still battling reanimen that just kept coming. Upon seeing Invincible he raises his guard again, but much to his surprise he's not attacked again, quite the opposite.
"Cecil, stop them!" your Mark exclaims into the comm as he jumps in between the crowd of cyborgs, giving a quick nod of acknowledgement to his other self. "He won't resist if we take him prisoner, right?"
"Sure..." the variant murmured, raising a brow in confusion. But indeed, the mechanical soldiers stop and he gets immobilized by Mark without fighting back. He looks up to you as if seeking your approval, and you quickly rush to their side, scolding Mark for being so harsh with his precautions.
"Are you hurt?" you whisper as the GDA agents transport you back to the Pentagon by helicopter, only the real Mark having flown ahead. You however refused to leave the variant's side, even though you've been strongly advised to go home, at least until the situation was less intense.
"This is nothing..." The Viltrumite huffs in amusement that you were worried about him of all people. He looks down to the shackles around his arms and legs that could never actually hold him, daring to crack a smile which you gladly mirrored. "But thanks that you stood up for me...even though I still don't understand why."
"Because I believe in you, so you better not disappoint me!" you chant, whearing a quiet whimper escape his throat when you put a reassuring hand on his knee. "Everything is gonna be alright, I'm sure of it. We're gonna figure it out...together, okay?"
A few hours later and you were still waiting in a hallway of the GDA, the feeling of suspense only worsened by all the pitying and disgusted looks some of the agents were shooting you. It was understandable, of course, since they probably saw you throwing yourself at the enemy live and in HD.
"I couldn't care less about whatever you two got going on" Cecil explains with his usual stoic manner, "but he refuses to talk and we don't have time for this."
You knew the opportunistic geeze was at least partly bluffing - he's most likely already planning on how to utilize Invincible's affection for you to control him.
Upon entering the prison cell you gasped at the gigantic apparatus containing him, all of his limbs encoated by a metal you didn't recognize in order to keep him from making any move. Honestly, it felt like no matter what they tried, he was only here because he wanted to be. If you told him to break out right now he'd most likely wreck this place in one milisecond.
The variant's defeated features brighten as he recognizes who was paying him a visit, but the initial excitement was soon pushed back by his newfound guilty conscience. He didn't expect to ever see you again, let alone you voluntarily entering the lion's den.
"I'll accept whatever punishment you deem necessary" he rasps, greatly worried at the possibility of them using you against your will. "Just leave them out of this."
Cecil nudged the bridge of his nose, groaning exaggeratedly. It sure isn't easy making objective decisions when you're that emotionally involved with the Grayson family - although he'd never admit the soft spot he had for them.
Not to mention, this was a once in a lifetime opportunity to get his hands on one of the two literal strongest men on the planet.
"Well for starters you'll help with rescue and rebuidling" he ultimatively decides, talking to the young man like one would scold an unruly child. "Consider this your last chance. And don't you dare taking a break until this whole planet has recovered from the aftermath of your crimes. I don't want to see you eating, sleeping or even breathing without any supervision. Got it?!"
"Yes, Sir..."
A single gesture of his hand enough to make his underlings free the Viltrumite from his confinements. "Give him a new costume so he doesn't scare the survivors...and insert an ultrasonic implant, just to be sure."
Mark rubbed his sore wrists, baffled with this decision. He had expected nothing less than torture, that they'd experiment until they'd find a way to execute him...but this? Ridiculous. Hardly a punishment.
Not that he's complaining, though.
At long last, you were facing each other again, those brief hours of separation feeling like an eternity apart. Crazy to think you barely even know this man - well, the fact that he was so much like the original Mark may have messed with your perception of time...
...or you were simply going crazy as well, who knows. Anyways, it did not feel wrong. If anything you've never been this happy in years.
The Viltrumite seems conflicted, his muscles occasionally twitching out of the desire to be close to you, to touch and hold you and never let go again. But then he detects the tears of relief in your eyes, misinterpreting them negatively and backing off even further.
Right...he doesn't deserve to be anywhere near you.
"You didn't need to...you shouldn't be here." He faces the ground in shame, blinking back tears of his own as he speaks. "Not after what I did."
"Damn it, Mark..." you half-yell, half-whine as you run straight towards him, wrapping your arms around his torso as if to press all of his broken parts back together. "Just...shut up. I'm capable of making my own decisions, whether you like them or not."
What a strange one you were. He wasn't even sure if his dimension's version of you had been that amazing of a person.
"Can't argue with that..." His hands tentatively finding purchase on your sides, and you instantly feel him melt at the feel of your body against his. "But it seems like we won't be able to meet each other for a while..."
"I can wait..." you shrug, beaming up at him with an almost playful tone. "...as long as you promise to take me on another date, would you? Without robots and death-matching yourself next time, if possible."
Mark smiled.
He did so many times ever since you met of course, but it always seemed like he was mimicking genuine human interaction, as if he was forcing himself to put on a facade in order to make you comfortable.
But this one, right here, right now...it was real, and so, so beautiful.
Hopefully you see more of it in the future.
"Oh, I think after you've seen how far I'd go for you, it's safe to say I can't deny you any wish..."
Hii! I have an ask lingering in the background of my head. How would no goggles invincible be with a high sex-drived!reader? I heard that invincible variant is a little weirdo, lol. That is all. Thank you for your time. Just know your writing is amazing, and make sure to stay hydrated every day <3
That's like one of the freakiest ones😭 one of the less serious, and most creepy, very sadistic too. But he's funny. He's very similar to Mohawk!Mark now that I think about it🤔
He makes fun of you sometimes, calling you desperate, AS IF HE ISN'T ENJOYING THIS JUST AS MUCH, in fact, he might even have trouble keeping up, not because of stamina or indurance, but maybe because he's just not as horny. Although, he has his moments, I assure you. The more powerful and lethal and superior he feels, the more he'll seek you out (imagine him coming back home covered in blood after commiting mass murder and being like "honeeeyyy I'm hooommmeee!!!!" and you have really nice sex after)
Sometimes he pouts because he thinks you just want him for his body but then he remembers how "superior" he is, of course you know how much better than anyone else he is, actually , who carnes about what you think anyway😡
And noowwww you're in trouble
Just make fun of how weak other men are compared to him and you'll be fine
Notes: Of all the characters, Mark came haunting my brain for my birthday fic. It was supposed to be a Housamo fic dang it dang it! Inspired by Vivinos' "Beloved". Never beating the ViviMeng x Invincible allegations.
Synopsis: During the Invincible War, a certain variant couldn't bring himself to do what he wanted.
"I would run, I would fly, if you come into my heart."
He still remembers you.
Even after the tragedy, bloodshed, and loss; Mark can still remember you as clearly as yesterday's memory. You were like a butterfly, beautiful and free, even after going through so much change in your life.
You met when you reported the bullying he faces one day, as a transfer student who didn't know any better. Despite the staff not doing anything, you still helped him even after the peers around him continued the treatment. He remembers that you started carrying around a first aid kit after a few weeks, not for you, no, it's for him. While the other students left you alone for your stubborn behavior, the same cannot be said for him, which ends up with more injuries on his body whenever you two run to each other in the halls.
Mark didn't understand why you kept sticking around him even after knowing his situation, but you just smiled and treated his cuts when he brought up the topic. You went out of your way to care for him, protect him, and his suspicions about you slowly disappeared. He even had the gall to think of you two as friends as he slyly tries to know more about you to return the favor.
You were his only friend. The one who took the time to get to know him. The only one who truly saw him as Mark.
With your blinding smile and infectious personality, you were like the first rays of warm sunlight after years within the cold and damp embrace of rain. And he can't get enough of this light.
This is the first time he felt such warmth in such a long time. The first time where he could enjoy life as it is. The first time he had so much fun that he went home with a smile, something that even shocked his mom, prompting curious questions from his parents.
That's how they got to know you.
Debbie was proud of him for finally making a friend, and Nolan nodded in approval, before asking to get you over for dinner. This led to him shyly asking you to come over, before following up that it's alright if you didn't want to. But you agreed, flashing him a smile that made his chest hurt, before going over to your next class. As for Mark, he was ecstatic, you'd come over!
The dinner wasn't the only thing that happened that night. While his parents were a bit too invasive with their questions, you didn't mind, answering it truthfully with such confidence. But the embarrassment caught up to Mark pretty quickly, that he excused both of you to his room, before apologizing for what happened. You assured him that it's fine, and the two of you holed up in his room for the remainder of the night, having decided to sleep over due to how late it was.
Mark remembers that night. How the two of you stayed up to talk about just about anything: Seance Dog, superheroes, the new comic book shop by the alley, subjects you were sure you'll fail. And somehow, the conversation steered to Mark asking why you still stuck with him after everything.
He wasn't listening to your reply, too focused on how the faint light of his desk lamp shines behind your silhouette, outlining your features within the shadows. God, he wanted to risk it all that night. Mark leaned in before he knew it, pressing a chaste kiss over your lips while his hand goes over yours.
It was a short lived moment where regret immediately sank it and would've eaten him alive if not for your reciprocation, chasing over his own lips after he pulled away. With a kiss shared in the dark, you confessed that you liked him too. Mark thought that he could die happy that night.
He should've. He shouldn't have done that.
Someone was watching that night.
Not long after you two started dating, his powers awakened. Mark rushed to you the moment he could control his flight better, before bringing you to a tour in the sky, feeling accomplished upon seeing your amazement while you clung to him. He can be a hero like in the comics he'd read! He can be your knight, and you can be the damsel this time around. He won't be the weak boy you once protected anymore. You won't have to worry about him anymore.
That's why he was enthusiastic to join the Global Defense Agency, so he could further cement his dream. As an official hero, you'll definitely see him as someone who is strong enough to finally stand side-by-side with you. But you said that he doesn't need to be a hero to be one. You said that having him return to you safely is enough. Mark doesn't understand your worries. Can't you see? He's more than capable now! Nevermind a few more bruises and injuries! He's Invincible!
He can do anything, as long as you're by his side.
He's strong now, after all.
Then why... when his father turned on humanity, why couldn't he do anything? Betrayed by the person he looks up to the most, the one who taught him everything he knew, the one whom he thought would give his blessings should you and Mark get married one day, Invincible couldn't do anything but lay down on the ground, half-beaten to death. Nolan continued his preach about the inferiority of humans, but Mark couldn't care less. With the most powerful hero going rogue, he could only think about your safety at the moment. If his father, no, Nolan, goes on a rampage, you and his mom would be in danger.
He needed to go home.
Omni-Man must've heard him call out your name in a broken cry, as he procured a body from underneath the rubble around them, courtesy of his earlier actions. The sight made Mark choke a scream and a sob, but the older man looming above his defeated state showed no such expression, only lecturing him about the superiority of Viltrumites over measly, primitive monkeys.
Nolan dropped your mangled corpse in front of Mark.
Everything went black after that. Mark doesn't remember what happened, or how much time had passed. All he knew was when he came into, he was clutching your body like a lifeline, muttering apologies as he broke down, all while his father lay dead on the ground.
Humanity hailed him as a savior. He became the hero he wanted to be, defeated the villain and saved Earth, but at what cost? His whole reason for doing all of this is now gone. Mark couldn't even go to your funeral because he knew he won't be able to let go of the casket as it lowered to the ground.
He tried to move on, he really did! His mom even helped him! But no matter how many times he gets into a relationship, your battered face haunts him whenever he looks up, replaying the memory of your body falling from above.
Mark breaks a little every time it happens.
He wallowed in his sadness for years, replaying every moment in his life where the both of you were happy, where you two were just ordinary students unaffiliated with hero work. If he closes his eyes, he could still imagine you from all those years ago, laughing and having fun with him; it's an idyllic life that he has no right to experience anymore. Not when you're already gone.
It was his desperation that drove him to accept Angstrom's offer. The promise of having you again sparked life back in his body. You're alive out there, somewhere in another universe, and if he does his end of the deal, you'll come back to his arms. You'll be together again.
He won't have to be alone anymore.
It was almost ridiculous how easy he found you on the first day, just minutes before the actual chaos started. You turn to him with recognition in your eyes, calling his name and smiling just like how he remembers it. Ah, Mark wants to cry.
What is he doing, trying to snatch you away from your happiness? Why is he here? To destroy your world and force you to love the one responsible for it? No, he won't cause you any more pain. This time, he'll protect you.
"You should go home. Find mom and get out of the city."
He didn't elaborate further, only giving you a vague explanation about a villain attack about to happen. You left, confused, but followed his advice nonetheless.
And as he stares at your disappearing figure, he lets this butterfly fly past.
AU Thoughts/Headcanons | Variant Mark Graysons Blending in on Earth
So, my Roomie fics take place in an AU where the evil Mark variants actually did kill Angstrom and end up trapped in our universe. That got me thinking...
If the Mark variants actually DID settle down and decide to try to blend in to the main universe (since suddenly, they actually have to live there), would the GDA attempt to recruit them against bigger threats? (Such as, the Viltrumites?) Would Cecil keep it secret from Main Mark, or would Main Mark be assigned to sort of babysit them and make sure they weren't up to anything planet-bustingly evil?
I feel like, assuming they stopped wrecking the world, Cecil would consider it a waste to keep trying to take them down (considering he tried to let Conquest recover).
I also have to wonder how each of the Marks would react to being approached by the GDA/Mark on behalf of the GDA (Cecil is NOT teleporting to Sinister Mark—the Mark on record for saying he killed his own Omniman is NOT going to be taken lightly). I'm going to write down a few thoughts for my favorite Marks.
Mohawk Mark: Probably pretty easy to initially convince—after all, he suddenly has to live somewhere that he's not an emperor for the first time in who knows how long, and a paycheck from the GDA would make things a little easier. Definitely has an authority problem though, and is exceptionally difficult to get to actually follow orders. Fucks up multiple missions by showing off too much and causing high collateral damage.
Lensless Mark: Also pretty easy. He just wants to fight, hurt people, get hurt... Having the GDA find targets for him? Nice. Also pretty hard to keep him on task though if there's any nuance to a situation beyond "kill these assholes", and he's absolutely a one man wrecking ball who will probably cause as much destruction as whoever it is he was sent to take down, so... best for big threats only. He also probably picks fights with Immortal on sight. For funsies.
Shiesty Mark: No. Fuck you. Fuck off. He doesn't work for anyone. Except for when he does... because well, he's still gotta eat. He probably takes jobs for Titan. Since that mainly just makes him an enforcer for a crime boss, and not destroying the planet, the GDA mostly leaves Shiesty alone. Though they're definitely still watching him. Any non-viltrum loyal Mark is perceived as a potential asset.
Viltrum Mark: Speaking of Viltrum Loyal Marks... This guy is pretty much the GDA's nightmare scenario. He comes from a world where the Viltrum Empire took over Earth, so he can give the coming Viltrumites a step by step guide on how to get the job done. I also like to think that Viltrum Mark might know he's actually prince of the Viltrumites (hence the empire symbols on his shoulders—bro is literally carrying the empire on his shoulders), so his being there makes things incredibly complicated. I could see Cecil trying to negotiate with him behind Main Mark's back, since Viltrum Mark could tell him exactly what Viltrum-Ruled Earth looks like. Also, potentially he could broker peace with the Viltrumites if he can prove to them that Mark Grayson is the grandson of their late emperor. Mostly, he's a massive threat.
Omni-Mark: I could see him refusing to work with the GDA, but also deciding to play superhero on his own. He wears his father's colors for a reason, and while we don't know too much about his own world (other than the fact that the show makes it so that he killed his Debbie instead of his Nolan), his personality seems in line with the type who would do superhero stuff because he can and he feels like it, rather than trying to be a good person. It's a power trip for him. The GDA begrudgingly leaves him alone, but watches him closely the same way they watched Omni-man. Super weird for anyone who suffered during the Invincible War OR when Omni-man turned to see him flying around fighting Kaiju.
Sinister Mark: Last, because he's my favorite, and I think pretty interesting. Because it's implied that as horrifically evil as he is, he's actually still a hero in his own universe. In the comics, he talks about fighting villains, much worse ones than Main Earth has. I think he still had the Chicago fight with Nolan, but since Sinister Mark was training against much tougher threats than Main Mark, Sinister successfully killed his Nolan in combat in defense of his Earth. It's probably some warped bizarro twist on Main Mark's desire to protect what's his—instead of coming from good intentions like Main Mark, I headcanon that Sinister Mark was possessive about his own world, and treated anything that threatened his idea of what was right as something that needed to die, whether that was villains, or a resistance fighting against his tyranny. Since his home dimension is baseline more evil than Main Earth and produces bigger threats, I could see him thinking GDA/hero work is beneath him. If something's a big enough threat to pique his interest, maybe he'll check it out, but he's not going to sign on to work with some organization. He doesn't really care much about protecting this Earth, because it's not his. He might get off his ass and fight if he thinks whatever life he carved out for himself is in jeopardy though. I feel like, much like Shiesty, Sinister is probably working in organized crime to pay the bills (and stave off boredom). He's probably assassinating people or disposing of bodies by flying them into space. Earth just has a ton of corpses floating in its orbit now. That'll be fun for the Viltrumites to find upon entry.
My friend @carla7900 got me into Invincible and now i’m obsessed with Mohawk Mark to the point of actually sitting down and writing fanfiction with no plot whatsoever.
Also i made this right after publishing on AO3, and im already working on a second fic.
