Ari Marmell: Don’t Be Afraid of Guardrails
In this interview, author Ari Marmell discusses what goes into writing a tie-in novel with his new contemporary fantasy novel, The Eternal Warrior.
Ari Marmell is a graduate of the University of Houston’s creative writing program and writes a little bit when he has time left over between feeding cats and posting on social media. A professional author of fantasy, horror, and science fiction for well over two decades, Ari has written a screenplay or two, multiple short stories, a variety of RPG material, and over twenty novels. He currently resides in Austin, Texas, along with George—his wife—and the aforementioned cats. Follow him on Bluesky and Facebook.
In this interview, Ari discusses what goes into writing a tie-in novel with his new contemporary fantasy novel, The Eternal Warrior, his hope for readers, and more.
Name: Ari Marmell
Literary agent: JABberwocky Literary Agency
Book title: The Eternal Warrior
Publisher: Blackstone Publishing
Release date: May 20, 2025
Genre/category: Contemporary Fantasy, Action/Adventure
Previous titles: Dust (Obelisks, book 1), Ashes (Obelisks, book 2), The Iron Devils, Litany Of Dreams (Arkham Horror tie-in), Hot Lead, Cold Iron (Mick Oberon, book 1), Hallow Point (Mick Oberon, book 2), Dead To Rites (Mick Oberon, book 3), In Truth And Claw (Mick Oberon, book 4), In Thunder Forged (Iron Kingdoms tie-in), Thief’s Covenant (Widdershins, book 1), False Covenant (Widdershins, book 2), Lost Covenant (Widdershins, book 3), Covenant’s End (Widdershins, book 4), The Goblin Corps, Darksiders: The Abomination Vault (Darksiders tie-in), The Conqueror’s Shadow (Corvis Rebaine, book 1), The Warlord’s Legacy (Corvis Rebaine, book 2), Agents Of Artifice (Magic: The Gathering tie-in) Gehennal, The Final Night (Vampire: The Masquerade tie-in)
Elevator pitch: For millennia, the immortal Gilad Anni-Padda has stood between humanity and supernatural, monstrous threats most people could not even comprehend. But now, his memories stolen from him by cultists of the god Nergal, Gilad must reclaim who he is from an enemy with access to his most dangerous secrets.
What prompted you to write this book?
Well, I’d love to share some moving story about a spark of inspiration or stumbling across a detail in a historical documentary that ignited everything to follow. But as this is a tie-in novel, the truth is simply that I was approached by Brendan Deneen at Blackstone, with whom I already had a longstanding working relationship, when he needed an author with a proven track record in action fantasy and licensed properties. So, I guess what prompted me to write this book was a combination of opportunity, an interesting character, and past experience.
How long did it take to go from idea to publication? And did the idea change during the process?
If we’re talking about the idea of “an Eternal Warrior novel,” it’ll have been a little shy of two and a half years between the time I came on board and publication. If we’re talking about the specific story elements, though, I’d say probably closer to a year and a half.
And yeah, it went through quite a few iterations. With a tie-in novel like this, it’s not enough for the writer to have a story they like. It’s got to be something the writer, the editor/publisher, and the licensor (Valiant Comics, in this case) all like.
At first, I had a story concept everyone was on board with, but after sitting with it a while, I realized I had some issues with it. (Yes, I had “creative differences” with myself. Anyone can have them with someone else, but when you’ve been doing this as long as I have, traditional hurdles and problems aren’t satisfying anymore, and you have to master far more advanced forms of putting obstacles in your own path.)
I think it was the third or fourth story concept that we finally ran with—which is good, since it’s the one that allowed me to get deepest into who Gilad is as a character.
Were there any surprises or learning moments in the publishing process for this title?
You know, there really weren’t. I hate to give that as my answer, since it’s boring, but it’s also true. On that side of things, the process went very much like the other tie-in novels I’ve done.
Were there any surprises in the writing process for this book?
Here, though, I can be at least a little bit more interesting.
Every tie-in novel is the product of multiple contributors, even when there’s a single primary author. Partly that’s just true by definition, since tie-in builds on characters, setting details, and/or plots initially created by someone else. I’m talking about more direct contribution, though. In most cases, story concepts and characters for a tie-in novel have to be approved by editors, by licensors, and so forth. Very often in that process, said editors and licensors will make their own requests, suggestions, or mandates.
In the specific case of The Eternal Warrior, though, the general structure of the plot was a full-on collaboration between myself and Brendan, my editor. That makes this my first book, after about 20, that I wrote based on a foundation—on an outline, basically—that someone else significantly contributed to. It wasn’t a dramatically different process, so the “surprise” was really more about how it felt than anything I can realistically convey, but it was a change.
Oh, there’s also a significant character in this book with a demographic identity I’ve never written before. There are always surprises involved in doing that, at least if you’re doing it right, if only because writing from a new perspective makes you—or at least should make you—question certain basic assumptions and viewpoints. (I’m being deliberately vague to avoid spoilers here.)
What do you hope readers will get out of your book?
For the most part, if they simply have a good time with it, a few moments of excitement or suspense or just passing distraction, I’ve done my job.
That said, though, I’d love for existing fans of Gilad to discover that they’ve got a brand-new way to appreciate the character they already love. I hope that they find it rewarding to get into his thoughts and beliefs through different paths.
And just maybe for a couple of readers to re-examine a few of their own beliefs in light of those held and espoused by a multi-millennia-old immortal.
If you could share one piece of advice with other writers, what would it be?
You mean other than “You should tell all your readers to buy my books after they’ve bought yours”?
Don’t be afraid of guardrails. A lot of authors worry that writing a tie-in, or working hand-in-hand with other people on a story’s development, will constrain their creativity. Make the final product less “theirs.”
But speaking as someone who’s done plenty of both sorts, working with an existing property, or on an outline partly developed by someone else, isn’t any less creative than starting with a blank slate; it’s just a different kind of creativity. It’s “How do I best use the ingredients that are available to make the dish that was requested, while still making it my own?” It’s a fascinating process. More than that, you’ll learn more about your own craft, and you’ll be stronger for it.
