a collection of theories, prompts, shorts, and oneshots, with our favorite character and her interactions with various bats (and others!)
everything is free for you to continue or elaborate on if you wish, but please give credit if you do!
Anon: I saw your Cass x Marinette one shot. How would the Batfam and/or JL react to Marinette?
Wait nonono I had these in bullet points noooooooo
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Bruce:
"Are you sure I'm not allowed to adopt her?"
"Well, if you do ever change your mind, I already have adoption papers prepared."
Welcomes Mari to the family with only a tiny bit of snooping into her background, because Cass is scary.
Still wishes that he could adopt her, but she's going to end up part of the family either way, so whatever makes Cass happy works for him.
Dick:
"Another one, B?"
"What? What do you mean you didn't adopt her? She fits all your criteria!"
"Oh. OHHHH."
Lots and lots of hugs and squeals.
Instantly accepts her as a sister.
They're gymnastics buddies now. He absolutely refuses to lose to her in a stretching contest.
Does his best to be a Mom™ and tries to cut her off from coffee too.
"We already have one coffee gremlin. Two of them will be unstoppable."
Jason:
"New Wayne?"
"Cassie's girlfriend?"
"All right then. Am I allowed to corrupt this one?"
"So Bats can convert everyone to his methods, but I'm not allowed to teach even one of his kids to fire a gun?"
"You already know how to fire a gun? I want to see this."
Mari isn't as good as he is, but boy is she close.
Declares Marinette the best Wayne after Cass, because it's universally agreed upon that Cass is the best.
Spars her a lot. Their skill levels are perfectly matched, so he only gets his butt kicked about half the time.
Tim:
Starts running a background check as soon as Cass tells them about her.
"Her name is Marinette, you said? I've got eight Marinettes that live in Paris with an age within five years of yours. Ooh, look, this one looks like Ladybug. Marinette Dupain-Cheng. Is that her?"
When he meets her in person, the first thing he does is ask if Adrien knows about the voicemail incident.
"Of course I know about that. Had to make sure that you were good enough for Cass, didn't I?"
Once Marinette proves herself (aka bribing him with delicious coffee-flavored sweets), they become coffee buddies.
That mostly consists of helping each other sneak in coffee beans for their secret stashes when they are cut off from it by their family, but it also involves the occasional outing to a cafe where they make various baristas nearly wet themselves.
Damian:
Challenges Marinette to a duel for his sister's hand.
"Cassandra only deserves the best. Are you worthy of my sister?"
It was originally a duel to the death. Cass stopped that with a look.
They fight for an hour and a half before Marinette finally pins him to the ground.
He is (mildly) impressed and allows Marinette to 'continue courting my sister.'
Marinette finds out about his childhood and has to be stopped from portalling over to Nanda Parbat and killing both Ra's and Talia.
"First Cass, now Damian? How dare they?"
Anyway, since she's not allowed to murder, she settles for making all of Damian's favorite childhood foods. Every. Day.
Steph:
"You're Marinette! Oh my gosh, you're the girl who makes Cass go all pink and flustered and-"
Cass tackles her to shut her up.
"We're besties now. No takebacks."
Marinette tries her best to get Steph to stop eating so many waffles with other tasty treats, to no avail.
"Yeeeah, those were great, but waffles."
Babs:
"Think twice before you enter the Wayne household, Marinette. Seriously. It's f*cking crazy in there, and once you enter, they'll never let you leave."
"Oh no. You've already met them, haven't you?"
"Well, I tried."
Does a deeper background check than Tim, somehow.
"Did you ever tell Adrien that you made the scarf?"
"How do I know? Security cameras, duh."
Batman is scary, sure, but Oracle is the truly terrifying one.She knows everything. Literally everything.
Including which Hello Kitty stickers Marinette used on which folders for each subject back in collége.
Duke:
Stares into her eyes very seriously.
Continues doing this for a very long time, until Marinette is positively sweating.
"Save yourself before it's too late."
Behind him, a crash sounds as Jason throws Tim off the side of the stairs, just as Dick walks past.
A paintball whizzes by his head as Damian charges in, screeching a war cry.
Cass joins the fray and takes them all down in thirty seconds, standing victorious, until she's sniped by a paintball and dramatically falls to the floor.
Alfred is holding a second paintball gun.
Alfred wins.
BONUS
Clark:
Is at the Manor for an interview.
Enters the living room to see them all congregated on various seats.
Eyes glance over Marinette at first.
Blinks, then looks at her again.
"Bruce. Did you get another kid?"
Marinette cheerfully informs him that she actually turned down the adoption papers.
"I-is that allowed? Is that allowed???"
Diana:
Also declares herself Mari's mother.
"She is a fierce warrior, this one. I must take her under my wing."
"You are the wielder of the Ladybug miraculous as well? Well, since Bruce has not managed to adopt you, I must do so now. Mother would love for her successor to be her granddaughter."
Is disappointed when Marinette insists that she has 'two parents, both alive, and I am very happy with them!'
"Alive, you say? Do you need me to fix that?"
"NO!"
"Well, all right then."
Decides to be her mother in spirit.Starts showing up at the Manor weekly to train her.
