Work Text:
Once upon a time...
Chauncey the Bear, made by its imaginary creation from Bill Cipher...
Chauncey looks at his hand claw, furry brown body, and the giant claw, who doesn't know anything...
Just then, he saw the triangle like Bill Cipher, yeah, really bad.
"Hey, I made you for my gift because you're on my list! And you wanna conquer the world! Join us so that the world will be mine forever!"
Chauncey is initially interested in him, but since he realizes he is just a bear, he turns back, ignoring Bill's help.
"Fine! However, I created you, so... have fun here! I'll go with my partners to destroy the Gravity Falls!"
Bill is laughable left and Chauncey is alone without any help from all other demons until when Bill is destroyed at the moment, including his partners, Chauncey suddenly realizes... Since he hadn't joined the battle, his only survival as a demon unseeded his identity: BEAR. Chauncey laughed at the void, then used his imagination to create a door portal, once he opened a door, it took a long path to reveal the basement where young Gloria is here.
Gloria was depressed in the locked basement by her parents due to the latter abuses and torture as Chauncey, as a toy form, came to her back, and found the nametag on her shoulders.
"Gloria?"
Gloria turned back, unrealizing that he was a demon, Gloria said, "Please, I wanna have a friend that can play with. Are you alone?"
"Yes."
"Then I'll make sure we both be friends forever and ever and I'll show a good person forever. I promise."
She grabs Chauncey the Bear and influenced by Chauncey's powers, kicks open the locked door of the basement, shocking the parents, then Gloria... lets malevolent powers to the parents that she's okay with the bear. However, things not getting well...
The parents discover her malicious powers, and they try to stop her, but the bear's influence is so strong, that he poses an entity version that consumes their minds and souls via vision, making both parents mad that they throw a toy back to the basement, and then killing themselves by knife stabbing to the heart-
Gloria returns to normal, haunted by her parent's brutal death, and a haunted presence by Chauncey... "I'll keep you in a nice place forever." As he has gone via the door, Gloria becomes traumatized and even later manipulated by Chauncey the Bear.
Then Chauncey successfully fed many children's souls via the inviting portal and his manipulation made their relative lose sight, and then...
He saw curly hair with two headbands, wearing a cute pinky skirt... and crying about her mother's death.
"Hey... Is that you? I want to make your friend forever."
She was to be revealed as...
Jessica.