A Journey through Shadows: Emma's Metamorphosis into Seviathan, the Enigmatic Demon

Question: Write a transformation story of Emma The Dylanus (an original character made by the Deviantart user Dylan613) turning into Seviathan von Eldritch (Charlie Morningstar's ex-boyfriend) from Hazbin Hotel (a TV series made by VivziePop), complete with gender change, clothes change, age progression, height progression, and mind/mental change (with Emma's personality and memories being completely replaced with Seviathan's personality and memories, despite her, now his, best efforts on fighting these new memories and personalities). For Emma's appearance, she is a 4.7 foot tall, 15 year old girl who has a lean build for her size, tan skin, long blonde hair (that reaches the back of her neck), and has deep chestnut brown irises. She wears a pink jacket, a lighter pink shirt, gray bra, short, small dark red skirt, dark purple leggings underneath her lighter purple shorts, a pair of pink socks and light gray tennis shoes with a pink heart on each of the shoes' tongues. Emma is a somewhat serious, very considerate, and kindly character, who is the same age as her boyfriend Dylan. Despite her small frame and being a teen, she, along with his boyfriend Dylan, goes in the way to protect her homeland against various villains and monsters (always successful, even if some are more difficult than others). Despite these traits, she does have some flaws, such as her occasional annoyance to Black's technology-making habits that causes problems (for Emma, Dylan, and others), being quite weak without superpowers (which she actually does not have and only obtains them when using special devices), and has fear and demons alike since she views them as nothing more than pure evil monsters. For Seviathan's appearance (after Emma turned into him), he is a humanoid demon with dark bluish gray skin and dark green hair with gray roots. He has dull red eyes with neon green irises. He has thick eyebrows and his mouth is filled with neon green colored sharp teeth. He has no visible ears or nostrils, giving him a less "human" appearance. He is seen wears a green coat with neon green trimmings, green pinstriped pants and a green hat with a light green trim that has eyes and a toothed brim. His suit is accompanied by a neon green ascot and undershirt. Sporting a charismatic exterior concealed beneath a facade of a confident and self-assured "dudebro" persona, Seviathan's life trajectory has been fundamentally shaped by the imposing weight of his family's expectations. For his personality, he is like the rest of his family, hiding behind a façade of power, confidence, and dominance, appearing as the type of demon the denizens of Hell aspire to be like. His public image is that of a rich, young, "chad" playboy or jerk jock who surrounds himself with expensive cars and models, spends the majority of his time partying at prestigious nightclubs, and is swooned over by millions of female demons, even coming equipped with an entourage of demonic sirens who sing entire songs devoted to how he's more "perfect" than everyone else. Never short of snappy one-liners, he boasts his family's influence, wealth, and power and is very sarcastic and passively rude towards others, throwing at time childishly cocky or elitist remarks at most people's sentiments, only ever restraining himself when speaking to his parents. Contrary to his outward appearance, Seviathan employs his confident facade as a shield to conceal a profound struggle with depression. Operating under the mask of a "dumb jerk chad," he strategically navigates a persona that contrasts with his genuine emotional state. While the world perceives him as a seemingly brash and confident figure, his true nature belies this image. He possesses a high level of intelligence that's obscured by his assumed persona, and he carries within him a tragic narrative shaped by centuries of both physical and psychological abuse inflicted upon him by his own family. This history of mistreatment has left him as a poignant and misguided individual, fractured by the weight of his past.The charismatic and somewhat dismissive demeanor he displays serves to uphold his family's outward reputation and to meet the expectations of his overbearing father. This charade is rooted in his desire to prevent the horrifying fate that awaits him should he falter in executing his father's ambitions. While charismatic, somewhat rude, and laid-back, he has a very "done with everything" attitude, and is clearly depressed and unmotivated. Deep within, he harbors a longing for genuine affection, a sentiment he carefully guards due to its taboo nature in the Hellish society. When not at parties or gatherings he tends to keep to himself in his palaces and maintain his exotic fish collection, read books and watch bad Hell Idol auditions on Voxtube. Mostly as a result of his public persona, Seviathan is quite a ladies' man, having dated numerous female royals and supermodels in order to keep up appearances (which has gotten him into many controversies and scandals), though most of these relationships were very shallow and without love. He is considered to be very attractive among Hell's society, with Charlie, Verosika, Angel Dust, and Asmodeus commenting on his good looks. He is deeply insecure over himself and incredibly desperate to win his father's good graces, showing extreme anxiety at the thought of being discarded like his thousands of siblings. He has the tendency to deflect or react irritably if others attempt to reach out to him or express sympathy towards him, as shown by him threatening Fergus and Charlie on the occasions they attempted to convince him on leaving the Envy Ring to escape his family. There should also be quotes from the characters in this story so we know what they're saying and what they're thinking.