Inspired by Sirsackballington GDA Mark AU. You know me, Im a sucker for any media with adoptive father trope (bonus points if he never planned to become a father)
I just adore the idea of Mr "brought order to chaos in prison" being terrified of 3 kids. And I mean, they all have superpowers, so there's a reason for the stress 🧂🧂🧂
✨ INVINCIBLE AU LORE DUMP (Post-Invincible War AU) ✨
Hey y’all, I’ve been working on an Invincible AU where things don’t just go back to normal after the Invincible War. People rebuild—not just cities, but the system. The trauma’s too real, and characters actually grow from it.
🚨 INVINCIBLE AU – PART 1: REX STEADMAN TAKES OVER 🚨
So here’s the setup: This AU takes place after the Invincible War, but instead of the world just shrugging off mass destruction (as usual), people actually change. Rebuild. Mourn. Get angry. And take power into their own hands. And leading that charge?
Rex Steadman.
Yes, Rex Sloan—but in this AU, he takes Cecil’s last name because… well, Cecil adopts him. Long story short: Rex nearly dies in the Invincible War (his entire skeleton explodes), and Cecil finds what’s left of him in a burning building and says, “Yeah, I’m not letting this kid die.” Cue cyborg Rex, rebuilt with synthetic skin, fried nerves, and basically just a brain in a metal body.
Cecil takes him in—not as a weapon, but as a person. And for the first time, Rex is treated like something other than a science experiment. So he starts living with Cecil around age 14–15 and never really leaves.
After the war, Rex finds out:
• Mark spent most of it in a hospital bed with Eve, instead of helping save lives.
• Immortal and Dupli-Kate straight-up quit during the chaos.
• Rudy stole his DNA, and no one gave a crap.
Rex finally snaps. He tells Cecil the system is broken. Heroes are failing. He’s sick of everyone treating everything like it’ll fix itself.
And Cecil? He’s injured, exhausted, and out of options. So Rex says, “Let me take over the GDA.”
Cecil: “You’re literally limping.”
Rex: “Doesn’t matter. I get it now. And I’m done playing the clown.”
Cecil gives him temporary control… and Rex kills it. Keeps casualties low. Mobilizes real strategies. Yells at Mark. Yells at Kate. Yells at Eve. It’s a whole tour of accountability.
Eventually? Cecil retires. Rex takes over full-time as the new GDA Director.
NEW ERA REX
He gets his own apartment. Sleep schedule. Real leadership skills. People respect him more than they ever respected Cecil. Even Cecil admits it.
Rex may be scarred, stitched together, and missing an eye, but he’s the most functional version of himself he’s ever been.
He gets his own apartment. Sleep schedule. Real leadership skills. People respect him more than they ever respected Cecil. Even Cecil admits it.
Rex may be scarred, stitched together, and missing an eye, but he’s the most functional version of himself he’s ever been.
Also, yes, he’s dealing with kaijus now. That’s a thing. We’ll circle back to that.
SHAPESMITH (AKA “RUS LIVINGSTON”)
Alright, it’s time to talk about Shapesmith—or as he’s now known: Rus Livingston. (Yes, that Rus. And no, it’s not creepy. Let me explain.)
In this AU, the real Rus Livingston dies during the sequid situation. Shapesmith survives—and since he already looks just like Rus, he quietly takes his identity. Publicly, he’s Rus. Privately? He’s still a Martian, still awkward, still figuring out how to human… very badly.
The only ones who know the truth are the GDA (now led by Rex) and a few trusted heroes. Everyone else just thinks Rus made a miraculous recovery.
TORTURE BACKSTORY (SORRY)
After the Invincible War, one of the evil variant Marks—Lensless—captures Shapesmith and drags him into his dimension. Shapesmith regenerates too quickly for the torture to really “stick,” so Lensless… improvises.
He injects him with a serum to make the wounds stay. Every finger, every face, every limb he rips off starts to scar. Over time, Shapesmith’s whole body ends up covered in burns, cuts, missing pieces. These scars are permanent, even in Martian form. He literally can’t hide them anymore without burning up energy he doesn’t have.
Eventually, Rex (with Angstrom’s stored powers) rescues him. Lensless might be dead. Might not. I’m still deciding.
POST-TRAUMA SHAPESMITH
Back on Earth, Shapesmith devotes himself entirely to Rex, who saved him. There’s something deeply Martian about that—life debt, loyalty, etc.—but Rex is just like “okay, weirdo.”
He doesn’t go back to being a superhero. Now, he’s Rex’s right hand—the Donald to his Cecil—handling alien affairs, diplomacy, research, space threats, and anyone dumb enough to poke an alien colony without permission.
He also helps Rex at home. They live together. Shapesmith wears suits and tries to “human” and still gets confused about normal things like rent, grocery stores, and personal boundaries.
OK, I had to shorten this for Tumblr so I’m gonna put a link to the Google doc with the information I have so far it goes over a more in depth lore of shapeSmith and Rex along with talks about the designs and my future designs. I will be posting more later so Mark, Cecil, eve and I will probably touch on the variance too so just be posted. Thank you 
OK before we start this is gonna be a lot of text like a lot of text cause I’m gonna load dump real quick for my invincible AU dimension ski