Authors POV: 2 months after Kaeya and Diluc's duel, the brothers and Dottore (Beta build) are at Delta's (webttore) lab, which holds Collei, they are there to get her out of the torture.
--------------------------------------------------------------"So, here is the plan. You two go in, deal with the segment, and whatever abominations he has down there, and get the young girl out of this hell, " the tall man with long, light blue hair and glowing red eyes tells the red head and his dark blue haired brother. "She will probably be traumatised and attack me if I interfere."
"Understood, Zandik." The brothers said
The two brothers make their way through the laboratory, Kaeya lighting the way with his pyro delusion as its bright blue flame illuminated the long corridors.
They turn a corner to see Delta build, experimenting with his assistants corpse. They break in weapons drawn and destroy the abomination that was his assistants corpse with both their fires.
Delta gets royally passed off at losing his research and tries to attack Kaeya with a sword. Kaeya blocks every attack and immobilises the insane segment by cutting off one of his legs and both of his hands in two swift slashing movements. He then called Beta to extract his rogue segment from the building while they looked for the child experiment.
They search for a short period until they come across a cell containing the traumatised child. They open it with a combined blast of blue fire and regular pyro vision fire.
The green haired girl cowered into the corner until Kaeya said, "Come with me, you're safe now." She took his hand, and then he lifted her up into his arms, an obscure looking sword floating behind him. Diluc questioned how Kaeya was so good with children and then realised he'd been in Snezhnaya and socialised with the children more than himself.
They walk out of the laboratory building to see and hear Beta scolding Delta.
"I give you free will to experiment as you wish to expand my knowledge, but the first thing you do is to experiment on children with Archon residue." Beta said to Delta poking exposed parts of the arm machinery to cause him little bits of pain.
The sight of the man with long light blue hair triggered an emotion breakdown in Collei, and the Archon residue leaked out and took the form of a cobra while Collei passed out on the snow.
"Zandik, protect yourself. Diluc, try to get her body off the snow. I'll try to draw the attention of the essence." Kaeya told the two grown men behind him.
"Abyssal Lord: Frigid Splinters," Kaeya says, transforming into his Abyss Lord form for the additional protection and strength.
The 13ft tall monster wrestled with the giant purple snake, claymore clashing against fangs, rattling of his icy cloak and the ever-present abyssal mist his larger body gave off hung in the air partially disguising his movements from the others view. Collei was already awake again. She was wondering if the giant monster fighting what is essentially a dead god was the same man wearing an eyepatch that carried her out of her suffering. The snake like essence clashes with Kaeya, who, after a few precise swings of his Flamberge, forced it to relinquish itself back into Collei.
He floated down and detransformed, crouching down next to Collei and told her, "Do not worry about the maskless man with longer light blue hair, he won't hurt you, in fact, he has a soft spot for children."They take Collei to Mondstadt as a precaution, and as Kaeya has a technical rank as cavalry captain of the Knights of Favonius, he requested that Collei stay in the care of the Knights.
He had also gotten Lisa to contact a man from Sumeru who might have some knowledge on sealing magic to seal the Archon residue deep inside Collei so it would never come out again until it can be removed.
It was during this time of waiting where Collei started to call him "Big Brother Kaeya," and she had even gotten along with Amber. They were really close, so close they were best friends and even considered each other sisters.
Upon the arrival of the man from Sumeru ritual, Kaeya was the one to greet him. "So you must the General Mahamatra Cyno." Kaeya says to the man wearing a hood with ears like a jackal.
"How did you know that," Cyno said
"If I were to lie, I'd say I have contacts everywhere, but in reality, I read Lisa's Akademiya Contact book." Kaeya replied.
Lisa proceeded to slap the back of his head. "Ow! That is the second time this year," he said in response, rubbing the back of his head.
"What do you mean second time, I've only hit you once?" Lisa questioned.Kaeya then took her aside away from the others so his secret wouldn't get out and told Lisa about Rosalyne being like his mother figure and his duel with Diluc a few months ago. The only thing he left out was that he was a member of the Fatui and his true age of 524.
Once the sealing ritual was complete and Collei parted ways with them, Kaeya and Diluc made their way to the Dawn Winery. Kaeya made the excuse that he was going on an expedition so he could return to Snezhnaya and report to Dottore that Collei was safe.

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The Displaced (A Fatui Kaeya AU)
FantasyA humorous, serious and adventurous story involving Kaeya after the cataclysm. he is adopted by the Ragnvindr family but runs away after having his eyepatch ripped from his face and being called a freak. After two months, he finds his way to Snezhna...