Fullmetal Alchemist Sparked a Notorious Harry Potter Fan Fic — Now It’s Getting a Movie

Harry Potter fanfiction just went pro: SenLinYu’s Alchemised, from the creator of Manacled, swaps wands for necromancy and unleashes an alchemy-fueled saga with Fullmetal Alchemist energy—sending anime fans into a frenzy.

A beloved Harry Potter fanfic just made the jump to the big leagues, and anime fans are eating it up. SenLinYu, the writer behind Manacled, has spun that DNA into a full-blown original novel called Alchemised. Think Fullmetal Alchemist energy, but in a new world where necromancy replaces wands, vertical cities scrape the sky, and fights feel like a shonen episode you can dog-ear.

So what is this thing, exactly?

Alchemised builds out a fresh setting called Paladia, a place of gravity-defying architecture and very grounded stakes. The magic system leans hard into alchemy, then layers necromancy and brutal, strategic metal manipulation on top. There is a character named Kaine who turns metal into a weaponized language, and the whole place feels both ancient and futuristic at once. It is very Fullmetal-adjacent in vibe without reading like a copy.

The Fullmetal DNA (without cloning it)

Hiromu Arakawa, the creator of Fullmetal Alchemist, famously decided that real-world alchemy was such a contradictory rabbit hole that she built her own rules. SenLinYu looked at that playbook and made a similar call. As they told Rolling Stone, the research is a mess, so you build the version that serves the story.

"She tried to research it and be really accurate with it, and alchemy research was just so contradictory and did not make any sense. So she was able to be like, 'I am just going to do what I want to do with it then.' I was like, okay, I guess that I will do that too."

The result is a system with rules that actually matter in a fight. From Paladia's skyward cities to Kaine's metal-forward combat techniques, the book threads science, ritual, and a little mayhem into something that feels new while scratching that FMA itch.

Do the battles hit? Yes, loudly.

If you write a war story, the action has to deliver. SenLinYu borrows the kinetic clarity you get from shows like Avatar: The Last Airbender (yeah, I know, not technically anime) to keep every clash readable, tactical, and cinematic. Metal manipulation as battlefield chess. Necromantic duels with real consequences. It is not wand-flicks and quips; it is choreography with stakes, and it lands.

• Magic system: FMA runs on alchemy and the Philosopher's Stone; Alchemised blends alchemy, necromancy, and weaponized metalwork.
• Combat style: FMA favors tight, rule-bound duels; Alchemised scales up to war scenes with strategic metal control and cinematic staging.
• Worldbuilding: FMA gives you Amestris and big philosophical beats; Alchemised drops you in Paladia with vertical cities and a mix of historical and esoteric influences.
• Creator approach: Arakawa mixed research with creative freedom; SenLinYu took the same route, prioritizing clarity over contradictory lore.
• Fan roots: FMA started as original manga/anime; Alchemised grew out of the Harry Potter fanfic Manacled.

From fanfic to bestseller (and very quickly to Hollywood)

Alchemised hit shelves on September 23, 2025 and did not just debut — it detonated. It opened at No. 1 on the New York Times Best Seller list. The initial print run was 750,000 copies, and those moved fast. There were packed midnight launches and the whole fandom woke up all over again.

Studios noticed. Legendary Pictures — the outfit behind The Dark Knight Rises and Dune — scooped up the film rights in a deal worth more than $3 million, per Rolling Stone. That is not a toe in the water; that is a studio writing a check with a 3 in front of it.

Letting Manacled be Manacled

Turning a beloved fanfic into an original novel is not just a search-and-replace job. SenLinYu was pretty blunt about needing to let the old story stay in readers' heads while this one stands on its own.

"It was really a process for me to accept that [the readers] have Manacled. I have to let them have that and make this story stand on its own."

And that mindset pays off. Alchemised does not coast on nostalgia. It earns its audience with sharp worldbuilding, emotional payoff, and that slick anime-adjacent fight design. Inside baseball: Paladia's sky-high architecture and metal-driven combat are tailor-made for wild production design if the film gets moving.

Where to watch while you wait

If you want to chase the vibe: Fullmetal Alchemist: Brotherhood is streaming on Crunchyroll. The Harry Potter films are on Peacock and HBO Max.

Your turn: is Alchemised the sweet spot between fanfiction roots and Fullmetal-style storytelling, or just a really good parallel evolution? Drop your take in the comments.