How do I keep my own voice in what Proselon writes?

Left to itself, an AI writes like an AI, in a register that is competent and anonymous. Proselon's remedy is not a rule that forbids the anonymous register but an example that crowds it out. You give the co-writer prose that already sounds like your book, and it writes toward that instead. The wider question of authorship and voice is a guide of its own. This is the practical side of it, inside the app.

The store in your Style folder

Every book keeps a Style folder, and in it a store of example passages that show how the prose ought to read. These are not instructions about your voice. They are your voice, on the page, for the co-writer to imitate. The strongest entries are passages you wrote yourself and judged right, and Proselon treats the store as something to keep filling rather than to finish. A thin one is the usual reason a draft comes back flat, and a generous one, drawn from your best pages, is what pulls a scene toward sounding like you.

So the first and largest thing you can do is feed it. When a page of your own writing sounds the way the book should, add it. There is no such thing as too much here.

Approve the early scenes in your own voice

The co-writer learns fastest from what you accept. When it drafts one of the opening scenes and you work it until it sounds right, tell Proselon so, and the passages you approved join the store as fresh examples. Because a book leans toward the sound of its first chapters, that early approval does two jobs at once. It fixes the opening, and it teaches the voice every later scene will be measured against.

Give each character a way of speaking

The narrator's voice is not the only one that matters. Each character in your book keeps a profile among your worldbuilding notes, and each profile has a place to describe how that person talks, clipped or ornate, blunt or evasive. Fill it in for anyone with lines to speak, and their dialogue stops sounding like the narrator wearing a hat.

Correct it out loud

When a sentence rings false, do not simply delete it. Tell the co-writer what was wrong and, better, how you would have put it. Proselon keeps a record of the faults particular to your book and watches for them as it drafts, so a tic named once is caught the next time it appears. The voice you want is reached as much by naming what it is not as by supplying what it is.