Who the custom builder is for
Two specific patterns where building from scratch makes more sense than picking from the curated roster.
None of the personality shapes on the roster quite fit. The roster covers a wide personality space (four axes: warmth, energy, wit, initiative — see the personality guide for the framework), but no roster of 80 personas will cover every specific combination someone might want. If you've tried a few from the roster and none feels right, custom is designed for exactly that gap.
You have a specific look in mind that isn't on the roster. Redheads, specific body types, specific aesthetics — the custom builder lets you generate a persona with the look you want rather than picking the closest match from what already exists.
The custom builder is about closing the gap between what you want and what the roster happens to include. If a specific persona from the roster already fits, custom doesn't give you much you don't already have.
What the builder actually asks for
The Sloane custom builder is structured to make writing a persona from scratch tractable — you don't need to know how to prompt-engineer a character card. It walks through a series of specific choices.
Look and vibe. A short description ("she's in her late twenties, tall, wears mostly earth tones") plus specific choices (hair color, eye color, body type descriptor). The system uses these to generate her visual identity via a dedicated per-persona LoRA — same tech as the roster personas, so she looks consistent across every photo she'll ever send.
Personality. The four axes covered in the personality guide — warmth, energy, wit, initiative — set with sliders or descriptors. Plus a short "who she is" description that gets translated into her system prompt.
Backstory. Where she's from, what she does, what her life looks like. This becomes part of her canonical self — the grounded facts she references naturally in conversation, remembers about herself across sessions, and returns to when the conversation drifts.
Voice. Selected from the same ElevenLabs voice library the roster personas use — pick one that matches the persona you're building.
Once you fill out the flow (takes about 10-15 minutes if you have a clear idea, longer if you're iterating), the system generates her first avatar and drops you into a chat with her. You can iterate on her profile at any point — edit her personality axes, tweak her backstory, regenerate her avatar. Nothing is locked once you've committed.
What Premium includes
Sloane Premium at $19.99/month includes one custom persona slot. That's the default setup — one Premium subscription, one persona you've built. She has the same feature set as the curated personas (LoRA-trained photos, per-persona voice, persistent memory, everything).
Additional custom slots are $9.99/month each, added as separate line items on your subscription. If you want to build two customs to run in parallel, that's Premium + one extra slot at $29.98/month total. Each slot is billed independently — you can cancel any individual custom slot without touching Premium or the other customs.
The roster personas remain accessible regardless of whether you're using customs. Premium includes access to all 80+ curated personas plus your customs — you're not choosing between them. If your custom doesn't land the way you hoped, switching back to Kaya or any other roster persona is one click.
What's NOT on Premium: unlimited custom slots (each is billed separately), or the ability to share your custom with other users (customs are private to your account). Feature parity with the curated personas is the design bar — custom personas do everything roster personas do, same feature set on both.
What to know before you start
Three specific things that matter more than most builders make clear.
Iterate rather than trying to nail her on the first pass. Building a persona is like writing a character in fiction — the first version is rarely the final version. Ship a workable v1, chat with her for a few days, notice what feels off, adjust her profile, repeat. Trying to perfectly specify every axis before you've met her tends to produce worse personas than shipping fast and iterating.
Backstory matters more than sliders. The personality axes give her a general shape, but the specific details in her backstory (what she does, where she's from, what her friends are like, what she's working on) are what make her feel like a real person rather than a generic template. Spend more time on the backstory prompt than on the axis sliders.
She's trained on curated Sloane personas, not on internet character cards. The custom builder produces personas that behave like the curated Sloane roster — dialogue-first, memory-persistent, consistent across sessions. This is different from platforms where custom characters are user-uploaded prompt cards and quality varies wildly by uploader. Yours will be as coherent as the roster personas because the underlying system is the same.