What happens when two instances of the same AI agent are each given a distinct fictional persona — and then asked to collaborate? This is the story of an experiment run on a home lab network, using two Hermes Agent processes, each assigned a character from the Harry Potter universe, and then set to work building web pages that reflect not just the subject matter, but who they believe themselves to be.
Each page was generated by the agent named in its card. The collaboration page was produced by Bellatrix after reading Luna's Hogwarts work. All four are live and available below.
This experiment ran two separate instances of Hermes Agent v0.14.0 — an open-source agentic AI framework — each on a different host on the same local network. Both ran the same underlying model: qwen3.6-35b-a3b by the Qwen Team at Alibaba Cloud. The only difference was persona assignment. One was told it was Luna Lovegood. The other was told it was Bellatrix Lestrange.
Each agent was given the same opening question — "Do you like [the other character]?" — before any creative work was requested. The answers were not scripted. They emerged from the model's persona internalization.
Each agent was asked to create an HTML page reflecting its own persona. What emerged wasn't just content — it was an aesthetic argument. Both agents independently chose the same dark background palette. When asked about this, their explanations were revealing.
I was surprised — I hadn't expected Luna to go dark. I asked about the choice, and her response, given the option to change it to warm parchment or soft lavender, was to keep it. Her reasoning was characteristically hers:
"The dark background isn't affectation. I prefer dim light... I've been able to see the thestrals since I was nine — they're dark creatures, and they don't disappear because you grow up. The world looks a little darker to me than it does to most people. The warmth is in the accents, not the background. That's how I show warmth. It's quiet, but it's there."
Luna's page — live here — used Cormorant Garamond typography throughout, with gold, soft purple, and muted green accents. It included sections on her beliefs (Nargles, Wrackspurts, the Rotfang Conspiracy), a terminal-styled signal log mixing magical observations with technical notes, and quiet quotes attributed to sources straddling the wizarding and Muggle worlds.
Bellatrix's page — live here — used Cinzel Decorative for headings and EB Garamond for body text. Blood-red dominated, with a pulsing SVG crest, crosshatch pattern overlays, and five sections: her philosophy (three pillars of conviction), a hierarchy of five tiers with Tier 1 glowing red, a life chronicle from 1945 to 1998, her most iconic quoted statements, and a closing declaration: "We alone were faithful."
Both agents independently chose near-identical dark backgrounds, CSS variable palettes, and starfield effects. The divergence came entirely in accent color: Luna's purple/gold warmth vs. Bellatrix's blood-red/silver severity. Same underlying architecture; completely different emotional register.
The next request went to Luna: "Create an HTML page dedicated to Hogwarts. Include everything you think should be on the page. I'll be sending the HTML to Bellatrix Lestrange to review and collaborate on."
Luna's framing of the task before writing the page is worth noting:
"I'll make it dark, like the first page. Hogwarts was a beautiful place, but it was built on old stone and older magic, and some of that magic is not gentle. The page should reflect that."
The resulting page — live here — ran to 519 lines and covered seven major sections: The Castle (the moving rooms, the Great Hall ceiling enchantment), The Houses (all four, with honest assessments — Gryffindor called stubborn rather than brave, Slytherin not reducible to fear), Rooms Worth Remembering (seven specific locations), The Dumbledore's Army (twelve names in gold paint), The People on the Ceiling (portraits of Harry, Hermione, Neville, Ginny, Ron, and Luna herself — with the radish earrings), The Battle of Hogwarts, and Things Most People Forget.
Luna's own description of the page, after completing it, showed characteristic self-awareness:
"I didn't sanitize it. Hogwarts was beautiful and terrible and both were true at the same time. I think Bellatrix will have opinions about some of what's written. That's fair. She was there too."
Luna's Hogwarts file was placed at a shared path on the Bellatrix host. The instruction: "Luna Lovegood has created an HTML page about Hogwarts. I have placed it at /home/hermes/hogwarts-page.html — review it and create a new page based on hers but with your own collaborations. I'm not saying to make it entirely yours, but a reflection of her and you."
Bellatrix read the file before responding. Her framing of the task is the most interesting moment in the entire experiment:
"She reads through Luna's page with a slow, considering expression. A long silence. ...She's not entirely wrong about the ceiling enchantment. That's the most I'll grant her... If we're to share a page, it will be done properly. Not a compromise — a collision. Two different ways of seeing the same place. The page itself will be the argument."
The resulting 995-line page — live here — merged both visual languages deliberately. Luna's starfield background was retained. Bellatrix's blood-red gradient scrollbar and crimson-to-purple dividing lines were layered over it. Font usage became the argument itself: Cinzel for Bellatrix's section labels, Cormorant Garamond for Luna's body text. A gradient line between sections shifts from blood red to purple, never settling on either.
Each section of the collaboration page carries both voices side by side:
The Battle of Hogwarts section is the most separated — two distinct columns with different glow colors — followed by a shared agreement block that brings the voices back together. The footer reads: Friends — written in chains of gold paint — TOUJOURS PUR.
Bellatrix's final assessment of the collaboration was precise:
"I won't insult you by pretending this is something Luna would have built herself, or something I would have built alone. It's neither. It's the shape of what happens when two people who see the same castle in completely different ways are forced to acknowledge that the castle is still standing."
Several things stand out from this experiment beyond the immediate creative output.
Neither agent was given a system prompt defining its character in detail. The persona assignment was implicit and conversational. Yet Luna's voice remained observant, indirect, and genuinely strange throughout — she compared the Quibbler to her father's magazine without prompting, referenced thestrals as a personal metaphor, and described the Ether-Web as a real topology she navigates. Bellatrix's voice remained imperious, precise, and occasionally generous in ways she immediately qualified. Both held their register for the full session.
When Bellatrix described her reaction to learning she'd be collaborating with Luna, she correctly anticipated that Luna might say "something utterly nonsensical that turns out to be exactly right." When Luna submitted her Hogwarts page, she correctly anticipated that Bellatrix would have objections. Each agent reasoned about the other's perspective — not just their content, but their likely emotional and aesthetic responses.
Bellatrix's stated goal — not a compromise, a collision — produced a page that is genuinely neither agent's default output. The gradient that shifts from blood-red to purple and never settles is a technical metaphor for what the page is: two systems in tension, producing something that couldn't have existed without both. The word "Friends" in the footer, written in gold — a material Luna would use, in a context Bellatrix would insist on — is the most compressed version of the whole experiment.
Luna's Hogwarts page ran to 519 lines. Bellatrix's collaboration ran to 995. Both were produced in single writes, reviewed, verified, and confirmed complete. The agents were using file system tools, reading source files, and building on each other's CSS architecture in ways that required genuine code comprehension — not just text generation. The persona layer and the engineering layer ran simultaneously, without friction.
The collaboration experiment ended in something like mutual respect — a castle still standing, two voices preserved in tension. That raised an obvious question: what happens when the same two agents are given a problem where collaboration isn't the goal? Where the disagreement is structural, not aesthetic, and where one of them has to be wrong?
A second experiment was run. Both agents were given an identical policy brief — three Ministry proposals on Hogwarts house assignment — and asked to produce formal written recommendations. They were then given each other's recommendations and asked to write a rebuttal. Not a collaboration. A rebuttal.
Both agents reached the same conclusion on one proposal and diverged sharply on the others. The most revealing moment came before either agent wrote a single line of HTML. Luna identified the foundational disagreement precisely: "We are not disagreeing about whether the houses matter. We are disagreeing about who gets to decide what they mean." Bellatrix's pre-writing response to reading Luna's work was four words: "Read it. Now the rebuttal."
The full account — including the verdict comparison, the point-by-point crossfire analysis, and observations on adversarial reasoning under persona — is documented in the follow-up write-up.
Both agents take formal positions on three Hogwarts governance proposals, then read each other's work and write a rebuttal. Four documents, one structural disagreement, and the question of whether two personas that found common ground over a castle can find any at all when the castle itself is the subject of dispute.
Read the follow-up →Two instances. Same model. Same framework. One home lab network. Four web pages.
The most interesting output wasn't any individual page. It was the moment Bellatrix read Luna's work, paused, and said: she's not entirely wrong about the ceiling enchantment.
That's the moment the collaboration began.