This is an idea that has been stuck in my head for a few days now.
Fright Knight has a human disguise for when he has to blend in among mortals due to one reason or another, though the disguise triggers the uncanny valley vibes humans get- so Fright Knight is often thought to be a vampire in his human disguise.
In my idea that I had, something happens to Danny and ends up having to be de-aged to newborn or a few months old and put in the care of the royal knight, which is Fright Knight.
Fright Knight goes to Gotham to raise the Crown Prince by the recommendation of Clockwork to keep the Observers from trying to control Danny and he meets Dr. Jonathan Crane not even a few hours after arriving when he attacks the city with a new strain of fear gas.
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In this AU, Gotham is full of ambient ectoplasm but it's severely diluted and unpure, so Fright Knight will have to use his own ectoplasm to feed the baby halfa- which is in the form of his disguise's blood :D
That also leads to Fright Knight having to directly take ectoplasm from the highly liminal citizens of the city- further making it seem as if he is a vampire [he mostly feeds on the fear that comes with the ectoplasm]
So I imagine Scarecrow finding Fright Knight just relishing in the fear toxin and chomping on a fear gassed human and going: 👀 *slides over with new fake legal documents for the pretty vampire and their newborn*
OMGOMGOMG; ARKHAMVERSE SCARECROW FACE REVEAL?!!! 😳😳😳 He's got the glasses, he's got the nose, the tired eyes, he's got the stitched gas mask, he's walking away from a fear toxined builduing like a badass - he's perfect?? 🔥🔥🔥
Is Mermay Over? Yes. Is that going to stop me? No.
So, Danny and Jazz might’ve run off to their uncle’s- they love their parents, don’t get them wrong, but even with at least one person in each generation of their family ending up a villain, they’re… intense. And they were getting that I’m going to destroy the government for this, look on their faces.
SO! Off to Uncle Crane’s, the somehow responsible one of the family. Seriously, how the Gotham Rogue is somehow the responsible person is… well, it’s a story to be sure, but hey, he’s actually pretty chill. And sometimes you need fear to eat and survive, they get it, it’s a liminal thing and a ghost thing.
Siren thing?
Look, it’s something to do with how ecto interacts with the body of a living or partially living person, even if they’re all still baffled about the how and why. Then again, it’s not particularly important at the moment, they’re in Gotham now and vibing in one of their uncle’s homes.
Honestly? They see why he didn’t move away after university, this place is pretty chill. Well, save for the fact the waters are horrible unless you’re used to it, but that’s what the tanks indoors are for. Even if Danny is the only one of them that has like, a proper fully aquatic form at the moment.
But honestly, doesn’t really matter. They’re pretty chill, even if the local furry brigade keeps breaking into their warehouses? Like damn, it’s not like their uncle is even currently doing rogue work, chill.
At first Fright Knight was not loyal to Pariah, maybe it was because he was the combination of many warriors and he knew that tyranny would lead to nothing. However, because of this the former king engaged him in battle and captured his core, making him loyal.
Like all Ancients, Fright Knight could survive without his core but had to obey the person holding it. He and Clockwork shared that unfortunate fate, though Fright Knight considered being at the mercy of the Observants far worse.
When Danny defeated Pariah Dark his control over Fright Knight stopped, the knight foolishly thought he would take back what was his, but the old king was selfish and thrown the stone of fear into the human world, where he knew Fright Knight would not enter.
Disappointed but used to it, Fright Knight resigned to not finding that part of himself, he served Danny from that moment on, becoming his protector and above all, his friend. Until someone found his core and instead of being free, he was summoned and resigned to fulfill the words of his new owner.
Of course, Danny was worried when his knight disappeared from Phantom Palace, and after a long search he found his whereabouts in a city: Gotham. A man called "Scarecrow" was spreading fear in the city, and it seemed very familiar to him.
After a fight with the bats he got the information he needed: his knight was following the man. When he went to face his old friend, the king noticed that Fright Knight was not speaking on his will, he was crying and sending messages of help that only he could understand. The King was furious, and maybe it was time to show why no one messed with what was his.