How Anime Helped SenLinYu Turn Alchemised from Fanfic into a $3 Million Movie Deal

Image: Del Rey

SenLinYu‘s debut dark-fantasy novel, Alchemised, surged onto the New York Times bestseller list in September — selling roughly 300,000 copies across North America its first week and reaching about 1 million sales in the U.S. by early October. The book’s commercial momentum even drew Hollywood interest: Legendary acquired the film rights, reportedly for a sum north of $3 million. Though the success might seem meteoric for a first novel, SenLinYu had already cultivated a devoted readership on Archive of Our Own, where the story began as Harry Potter fanfiction.

SenLinYu says the tale began in what felt like a narrow corner of fandom, but it quickly spread beyond their expectations. In a Zoom interview they described how the story “went viral,” moving through platforms in ways they couldn’t fully control — and how unauthorized sales of the work left them with limited legal options.

The author adopted their pen name from their AO3 handle after posting the widely read fanfic Manacled, a long-form reimagining in which Voldemort’s forces win and former classmates are forced into intimate and morally compromised arrangements. Over some 70 chapters, Manacled explored a coercive arrangement between Hermione Granger and Draco Malfoy, centering on captivity, interrogation, and an illicit romance that grows from extreme circumstances.

Alchemised retains the structural premise of Manacled but relocates the stakes into an original world: the conflict pits a staunchly religious order of alchemists, the Order of the Eternal Flame, against the Undying — necromantic forces who can resurrect the fallen to fight again, creating a tactical and moral imbalance in the war.

The narrative opens after the Order’s defeat. Helena Marino, one of the few survivors, is consigned to the household of Kaine Ferron, a former classmate and alchemist tasked with probing her memories for secrets. The novel includes a fraught romantic thread with unequal power dynamics, yet SenLinYu resists the label “romantasy” and rejects facile comparisons to works like Fifty Shades of Grey, arguing that fanfiction arises from a range of creative impulses beyond erotic fantasy.

Far from being a simple erotic exercise, SenLinYu emphasizes that fanfic writers often create from genuine, sustained passion rather than market calculation — a motivation that cannot be reduced to self-insertion or wish-fulfillment.

To shape the book’s tone and combat choreography, SenLinYu drew on darker animated works like Castlevania, while the mechanics of the protagonists’ powers were influenced by series such as Fullmetal Alchemist and Fate/Zero. The author says anime’s inventive weaponry and mutable combat scenes informed their notion of alchemical warfare.

Research into historical alchemical thought — including Neo-Platonic and Aristotelian strains that historically feminized emotion as a weakness — fed directly into the novel’s worldbuilding. SenLinYu intentionally embedded similar gendered assumptions into the origins of their magic system: whereas the world of Harry Potter tends toward gender parity, Alchemised imagines a fiercely patriarchal culture in which women rarely receive formal alchemical training and their potential affinities are often treated as bargaining chips in marriage arrangements.

Elements of Manacled took clear inspiration from Margaret Atwood’s The Handmaid’s Tale; in the fanfic, Death Eaters implement a breeding program to address falling fertility among purebloods. For Alchemised, SenLinYu initially excised that material before reworking it into an explicit eugenics-driven project within the book’s wartime atrocity framework.

Within the novel, members of the Undying assault captive women to engineer offspring with specific alchemical signatures — children intended as vessels for necromantic souls when those souls lose their original bodies. Helena is targeted for the program because she possesses rare talents: animancy, which manipulates minds, and vivimancy, the ability to shape living flesh.

Though vivimancy is denounced as an abomination by the Order of the Eternal Flame, commanders nonetheless exploit Helena’s gifts to mend soldiers and stabilize the wounded. SenLinYu likens her to Hel, the Norse figure who rules over those who die without glory, and describes Helena’s work as tending a nightmarish, makeshift hospital for the broken.

Removing the familiar Potterian cast forced SenLinYu to generate emotional stakes for new protagonists — many of whom are already dead when the story opens. To learn how to evoke a vanished but influential character, they turned to the anime Frieren: Beyond Journey’s End, which uses flashbacks to show a deceased hero’s continuing importance. Working from scratch also allowed the author to introduce original figures like Luc Holdfast’s sentinel, Lila: a woman written as a martial foil to Helena and informed in part by Athena’s archetype — a warrior coded as female who still navigates patriarchal constraints about purity and agency.

Alchemised is intentionally grim: it depicts self-harm, torture, and sexual violence as part of its exploration of wartime brutality. SenLinYu says they refused to sanitize the darker dimensions of conflict, arguing that literature and media too often flatten war into spectacle and heroism while eliding moral ambiguity, trauma, and the discomfort necessary to reckon with those realities.

Source: Polygon