Who This Book Is For
Readers who want dark progression fantasy with an anti-hero incubus, brutal world-building, and zero moral guardrails on the power fantasy
Who This Book Is NOT For
Anyone who needs a heroic MC, lighthearted tone, or content warnings to be deal-breakers -- this book has graphic violence, explicit content, slavery elements, and morally gray choices throughout
Our Review
The Setup
Dominick Stillwell was running for his life when desperation hurled him into another world. He woke up no longer human — reborn as an incubus, a demon with the power to enslave minds and bend wills. Survival in this brutal realm of slavers, mercenaries, and magic means mastering his gift before it consumes him.
Dom tells himself he is only punishing the guilty. That he is different from the slavers and tyrants he destroys. The book makes it clear, quietly and persistently, that he is lying.
This is not a power fantasy where the MC stumbles into a comfortable harem and everyone gets along. I, Incubus is a dark progression fantasy where every bond carries weight, every fight has consequences, and the line between justice and domination blurs more with each chapter. Dom accumulates power through his incubus abilities — intimate bonds that strengthen both parties — but the question the book keeps asking is whether the power is serving him or he is serving it.
What Works
The commitment to tone is the book’s greatest strength. Radcliffe does not flinch from his premise. Dom is controlling, ruthless, and increasingly indifferent to the moral cost of his choices. But Radcliffe writes him with enough self-awareness that you understand his rationalizations even as you watch them crumble. Readers on GoodReads described him as “dark and controlling, not afraid to use and discard people” — and noted they were rooting for him anyway. That is a difficult line to walk, and Radcliffe walks it.
The pacing is relentless. At only 141 pages, the book never has time to sag. Every chapter pushes Dom further into his new reality, escalates the stakes, and reveals more of the world. Reviewers consistently praised how smoothly the story reads from start to finish, with the world-building woven into the action rather than dumped in exposition blocks.
The world itself has real texture. Slavers, mercenaries, magical hierarchies, and demon politics all feel like they exist beyond the borders of what we see. Radcliffe seeds enough detail to make Arcanis (or whatever this realm calls itself) feel lived-in without over-explaining.
What Doesn’t
The writing quality is genuinely divisive. Some readers praised the detail and immersion. Others called it “AI slop” with structural issues. The truth likely sits somewhere in between — the story moves well and the ideas are strong, but some passages could benefit from tighter prose and more careful editing. Your tolerance for rough edges will determine where you land.
At 141 pages, the book is very short. It reads more like a first act than a complete story, ending just as Dom’s power and position are becoming truly interesting. Readers who want a meaty first entry will feel like they just got an appetizer. The series continues, but this volume leaves a lot on the table.
The content itself will be a hard stop for many readers. Graphic violence, explicit sexual content, slavery elements, and mind control are all present and unfiltered. The book earns its content warning. If any of those elements are deal-breakers for you, this is not the book.
The Heat
This is a 5 out of 5, and it earns that rating through both frequency and intensity. Dom’s incubus nature means intimate scenes are baked into the power system — they are how he grows stronger, how he forms bonds, and how he controls his environment. The scenes are explicit, varied, and tied directly to the dark fantasy tone. There is nothing soft or romantic about them. They are tools of power, and the book treats them that way.
Bottom Line
I, Incubus is not for everyone, and it knows it. Radcliffe has written a dark, fast, morally uncompromising progression fantasy that delivers exactly what the subtitle promises: a demon ascension harem. Dom is a compelling anti-hero, the world has real depth beneath the brutality, and the pacing never lets up. The short page count and divisive prose quality keep it from top-tier status, but for readers who have been searching for a harem book that goes truly dark, this is one of the more honest attempts on KU. Just know what you are walking into.
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If You Liked This, Try
Both lean into dark demon-powered harem fantasy with anti-hero MCs and explicit content, though Radcliffe goes darker on the morality scale
Shared incubus transformation premise with power growth through intimate bonds, though Radcliffe layers in more progression fantasy elements
The Verdict
I, Incubus is a dark, fast-paced progression fantasy that commits fully to its morally gray premise. Dom is not a hero, and the book does not pretend he is. Radcliffe delivers a full-throttle story with genuine world-building and a protagonist whose descent into power is both compelling and unsettling. The writing quality has divided readers -- some praise the pace and detail, others call it unpolished. If you can stomach dark content and enjoy watching an anti-hero accumulate power without apology, this is a gripping opener.