Fate's Deception: Sora's Rebirth into Helsa von Eldritch

Prompt: Write the transformation story of Sora (in his outfit from Kingdom Hearts 3) from the Kingdom Hearts game series turning into Helsa von Eldritch (from the adults cartoon/animated series Hazbin Hotel, made by VivziePop), complete with reality change (the world of Kingdom Hearts warping and turning into the world of the Hazbin Hotel) gender change, voice change, age progression, height progression, and mind/mental change (with Sora's personality and memories being completely replaced with Helsa's personality and memories, as the voice tells the changing being (formerly Sora) that he (or rather she) was never a mortal boy named Sora, since she was daydreaming all this time, and that she has always been Helsa von Eldritch, despite Sora's best efforts on fighting off his new memories/personality, making him, now her, fully believe in the voice in her head and know that she had always been a royal demon and a part of the von Eldritch family, causing her to completely forget she was ever a mortal boy named Sora and remembered that she had always been a part of the royal demon family, more specifically a member of the von Eldritch family, and herself being named Helsa von Eldritch (which is her true self and true life, unlike her previous life as Sora, which never existed and was only a daydream)). For Sora's appearance, he is a 15 year old boy who wears a black v-neck t-shirt with white hemming, black shorts with gray pockets like Dream Drop Distance held on by red straps similar to Kingdom Hearts II. Unlike previous outfits, his shorts are tight around his calves. He wears a longer black hooded jacket with red hemming, gray pockets with white hemming, and red flannel flaps that are held down by a series of yellow buttons. His shoes have the opposite color scheme of Dream Drop Distance with the ankle and tongue of the shoe folded down, and a single black strap. His gray fingerless gloves come to a v on his hands and are just short of his elbow. The gloves have red hemming, a yellow strap around the wrist, and a silver circle plate on the back of the hand like in Kingdom Hearts. His hair is significantly shorter and less spiky (although it is still spiky), and he continues to wear his signature crown necklace. Like most typical heroes, Sora is brave and heroic, impulsively risking his own life for people he doesn't know and is loyal to a fault. Despite everything that he has endured throughout his journey, Sora retains his upbeat and optimistic attitude. He shows little tolerance for cowardice and selfishness but is ultimately forgiving of those that are sorry for their actions. Sora has a remarkable capacity to forgive, even to those who have harmed him and his friends. For Helsa's appearance (after Sora turned into her), is that of a tall and hourglass-built demon with green-smoke skin, and long silverish-white hair that sports dark gray spots, similar to a cephalopod's tentacles. Her hair also features rather large bangs which covers her right eye. Her eyes themselves have neon-green irises, deep-teal sclera, slit pupils, and have thick upper eyelashes with smaller bottom lashes protruding from them. Her mouth sports black lips, and sharp neon-green teeth inside. Helsa wears a brink-pink coat with a neon-green fur collar and cuffs, as well as four neon-green buttons on the front, a greenish-black skirt with the same trimming as her coat around the bottom, and over-the-knee greenish-black heeled boots. Like some demons in Hell, Helsa has demonstrated the ability to change her physical form into a more fearsome and eldritch appearance when she is angered; when she enters her full demon form, as shown when she became enraged because Charlie Morningstar (the main protagonist of Hazbin Hotel) called her a loser during her song, she grows a more eldritch appearance with sharp-toothed mouths and eyes popping out throughout her body.. Personality-wise, Helsa is described as a "mean rich girl" (with a personality similar to Regina George from the movie and musical "Mean Girls"), as she is purposefully and deliberately mean to others. This was further supported as she is described as the "very smart kind of evil". There should also be quotes from the characters in this story so we know what they're saying and what they're thinking.