To Our Untamed Core

by Sonora Reyes, Sonora Reyes

The Hunger Games meets The Sunbearer Trials in bestselling and award-winning author Sonido Reyes’s YA dystopia about a boy who survives by hiding his truth until his boyfriend is sentenced to El Torneo — a brutal, fight-to-the-death game — where he must risk everything to save him.

Centuries after the conquistadors claimed the Afueras for their own, Temo spends his life obeying the Holy Order’s decree, undergoing their sacraments to tame his supposedly violent nature.

The only rule he hiding that he’s trans. If that fact is discovered, Temo will face El Torneo, a brutal, fight-to-the-death game pitting the untamed against one another. No Afuereño who enters El Torneo ever escapes with their life.

But when Temo’s boyfriend is unexpectedly arrested and thrown into the deadly tournament, he’ll do anything to rescue Ollin from his gruesome fate, even if it means entering El Torneo himself.

Only there's far more to this tournament than meets the eye—survival is just the beginning. When the cost of saving the one he loves the most might be higher than he ever imagined, is Temo willing to pay it?

Genres: Young Adult, Fantasy, LGBT, Queer, Dystopia, Science Fiction, Transgender

425 pages, Kindle Edition

Expected publication September 22, 2026

About the author

Author also writes under Sonido Reyes


Born and raised in Arizona, Sonora Reyes writes fiction full of queer and Latine characters in a variety of genres, with current projects in both kidlit and adult categories.

Outside of writing, Sonora loves breaking their body and vocal chords by playing with their baby niblings, and dancing/singing karaoke at the same time.

Reviews

[Yami · Rating 4 out of 5]

The beautiful: Reyes has a magical ability and talent when it comes to stirring feelings and creating relationships. Love. Found familia. Queer joy and queer wrongs 😂 as well as the Mexican sazón 🤌 love the multiple POVs. While lots of people are met in a short amount of time the characters building is on point! Need an Adult HEA online pls 😝

The representation: LOVE having a trans mmc 🫶 did feel like fluff in a sense where only a person in power is unsupportive-ish but high key we get enough BS in real life I feel like this is justified 🥰 plus the beautiful names and their strong personalities 🙌

The ugly?: In a way, I feel like you almost *have* to have read The Huger Games prior to reading this. Which thankfully, I feel like the majority of the people interested in this world, would have. Some situations felt like they barely touched surface. I agree having this be more of a duology would allow the reader to connect with characters deeper 👀 I have read all of Reyes’s novels and I just wish we had more time to fully go on the ride together 💗

[Sara Ratliff · Rating 3 out of 5]

This was an enjoyable read in the moment, and I have a decent number of issues with it. Most of my issues can probably be attributed to the fact that this is Sonido Reyes' speculative debut. There's some awkwardness in the world-building, and the plotting needed to be a bit tighter to fit everything he wanted in there.

Characters are where Sonido's writing usually shines, and I would say that mostly holds up here. There are three central characters, Temo, Socoyote, and Ollin. Temo is very compelling narrator. Socoyote was probably the most sympathetic of the bunch for me. Ollin was the weak spot. His story is the most interesting, but his personality is a bit flat until around the 90% mark where we see a bit of a break-through, and he starts to feel more human. The side characters in this book were less compelling than I usually find in Sonido's stories. Athziri, a 9 year old who is forced into el Torneo, frustrated me and I struggled to articulate why for much of the book. Athziri is emotionally immature (as a 9 year old ought to be), but her voice reads much older. A young child's immaturity articulated in the voice of a teenager was less sympathetic than she should have been. The primary antagonist, the king, is also a pretty major weak spot of this story. He's not only one-dimensional, but also cartoonishly incompetent, which made the plot resolution less satisfying than it should have been.

The romances were a mixed bag. I enjoyed Temo, Socoyote, and Ollin's interactions with one another. The romance is not super central to the story, but in developing three romances, there just wasn't room for everything. The romances heavily rely on these characters' history, but we only get a clear picture of Temo and Socoyote's mutual past. The conflict in these romances derives largely from miscommunication. It's a reasonable lack of communication given their age, but it felt petty next to the intensity of the plot.

This book takes place in an empire based on catholic spanish colonization of the americas. The atmosphere of this setting is pretty successful, but the details of how modern technology fit into this world confused me. The colonized people don't have access to advanced technology, which makes plenty of sense. But we also see the king's guard using swords instead of guns (which do exist in this world). This has significant consequences in the plot but I didn't see an explanation for why it was the case to begin with. Advanced technology only comes up when it's relevant to the plot, so it's a bit jarring when you're reading a book that mostly feels like it's set in the 1500s, and then someone pulls out a laptop.

The influence of catholicism in this world was very prominent at the start of the book — with Temo and his sister very entrenched in the colonizer religion, and with all of the colonized people forced to take the "eucharist" — but it fades to the background as the plot progresses. It surprised me, that in a queer book set in a world dominated by a catholic-inspired religion, homophobia and transphobia were discussed so little. Temo is a trans man, and we learn right off the bat that he will be imprisoned and thrown into el Torneo if anyone learns that he's trans. The plot brings us in a different direction pretty quickly though and it doesn't come up much after that. How these societies (of the colonized and the colonizers) view queer relationships, I have no idea — I didn't see any discussion of homophobia. I'm happy to read queer books that don't center on discrimination, but it surprised me given the setting and the obvious catholic inspiration.

The political messaging in this book reads a bit on the younger side of YA. At times, it's a bit mismatched with the level of violence portrayed. This isn't a super gory book but there are a few scenes that are more brutal. This book went further than I expected, not so much in the violence itself but in who it came from. I really enjoyed this willingness to have that severe violence be perpetrated not just by villains or strangers but by the protagonists. I do think though that these few brutal scenes sit oddly alongside the more intro-level political messaging, and it makes me wonder who the target audience is.

The political commentary is severely undermined by the weakness of the king as an antagonist. The king reads as a Trumpean figure. He's bumbling and incompetent, and always being indulged by everyone around him. He rewrites history by demanding everyone accept how he describes a situation, and he's constantly changing his mind while pretending it's always been that way. This isn't the only discussion of propaganda but it is the form we see directly on the page the most, and I think it's also the most unsuccessful. It seems to suggest that most of the propaganda in this world is just everyone indulging a delusional old man because he'll have them killed otherwise. I'm learning that analogues for modern political figures just don't fit well into second-world stories nowadays because they're so ridiculous that it makes any story feel like a farce.

I have mixed feelings on this one. Sonido Reyes is a very skilled writer and I love his narrative voice. I don't think this was a bad book by any means, I just don't think it was quite a successful one either. I'd love to see how he grows in this genre.

[Lance · Rating 5 out of 5]

Thank you to Netgalley and Sonido Reyes for this eArc, received in exchange for my honest review.

This book is a celebration. It’s a story of rebellion told through a deeply anticolonial framework, centering community, joy, and love. It hits like a gut punch, and ends with a gasping breath. Reyes weaves a masterful story with complex, compelling characters and incredibly detailed, vivid world building, which will lead readers to sleepless nights holed up with flashlights under their comforters.

Temo does his work, keeps his head down, and follows the decree of the Holy Order. Like everyone else in the Afueras, he knows stepping out of line will mean certain death in El Torneo, a death tournament which occurs every ten years. But Temo has a secret: he’s trans, and if the Holy Order finds out, he’ll surely have to fight in El Torneo anyways. Still, he’s surprised when days before El Torneo it’s not him who is arrested, but his rule-following boyfriend Ollin. No Afuereño has ever made it through the tournament alive, but Temo refuses to watch his boyfriend die. To protect those he loves, Temo breaks into El Torneo determined to keep Ollin safe and write a new end to the story.

Like I said before, the characters and world building were both very strong. I was rooting for Temo from the very first page, and the other POV characters quickly won me over as well. I often find that, in books with many different POVs, it can be hard to keep all the characters straight, but I didn’t have that problem at all. Each character was so unique, with their own personalities, strengths, weaknesses, and desires, that is was easy to keep them all straight. The large cast of characters was really a benefit for this book, which dealt so deeply with the idea of community-based resistance. I also found their relationships with each other very compelling. The romance element wasn’t the main focus, but it felt blended into the story seamlessly. It was cute and sweet, and allowed for more gentle moments to contrast the violence happening throughout the story. Additionally, the familial and platonic relationships throughout the story were lovely and full of care and understanding. The setting was also incredibly compelling, with the world being strongly steeped in Indigenous Mexican culture and Catholic ideology. The narrative is explicitly anticolonial, largely due to Reye’s world building.

As a trans reader, I often seek out trans narratives by trans authors, and Temo’s story didn’t disappoint. Temo’s transness wasn’t ever brought into question, or a cause for harm. Still, there was a very real fear associated with the consequences of being found out, which felt very relatable to my own life. I really appreciated the balance between Temo’s trans identity being a non-problem while still remaining important to the story. Trans characters getting to just exist and be loved will always be important to me, and Temo is a wonderful example of that.

For all that I really adored this story, I had a few critiques. There were many different threads throughout, to the point that some of them didn’t feel fully fleshed out. The action packed sequences of this story also sometimes seemed to come at the expense of the emotional payoff. While this book was pretty long, I ended up wishing it had been longer, or possibly a duology, in order to really spend time with all the different fascinating side plots and emotional moments. Still, I did really enjoy this book, and would recommend it to others. These things could have made me like the book even more, but they didn’t stop me from loving it as it is.

Overall, "To Our Untamed Core" was a journey I was glad to have taken. I adored Temo, Ollin, and the other main characters. The romance was incredibly sweet, and I also loved the platonic and familial relationships between characters. The world building was masterful, and the story kept me hooked until the last sentence. I hope other fans of "The Hunger Games", "The Sunbearer Trials", and queer kids bannding together to change the world will love this book as much as I did!

[Reese · Rating 4 out of 5]

I adored The Lesbiana’s Guide to Catholic School, so when I found out that Sonido Reyes was writing a speculative book I was so excited! Happy to report that I was not let down, this book was so well done.

The world building was fantastic, and all of the characters felt so real and distinctive. This book has multiple povs and this serves the story well. I absolutely loved Temo and Socoyote. I have more mixed feelings on Ollin, I think I would’ve liked to spend a bit more time with his character to really understand his backstory and motivations.

On the topic of Temo, Socoyote, and Ollin, this is the first book I have ever read with a true love triangle! Romance is not really a main concern of this story as they have more important things, like surviving, to focus on, but love absolutely is at the core of this story. Temo and Socoyote are both motivated by their love and desire to protect those they care about. All three boys love each other, and reading a book with an achillean, true love triangle, and one of the boys being trans-masc, is INCREDIBLE representation that I wish we got to see more often.

I have seen a lot of comparisons of this book and The Hunger Games, which I agree with. If you like The Hunger Games you will probably also enjoy To Our Untamed Core, but it is also tackling a lot of other issues. This is a story about colonization, oppression, and religious trauma. Whereas in The Hunger Games the Games are made a spectacle of entertainment, El Torneo is a brutal facade created to manipulate the masses. It takes a different angle than The Hunger Games in this way. The book makes you sit with a lot of uncomfortable things, like the necessity of violence in the world and situation they are in. It is brutal and unflinching. I found certain moments to be even more intense than in the first three Hunger Games books (I have not read the most recent two).

The pacing felt well balanced until the end, which seemed very rushed. I kind of wish this had been a duology, there is a lot I would’ve liked to have spent more time on in the ending/epilogue. As I already said, I also would’ve liked to have more time developing Ollin’s character, and I would’ve liked to see more of the resolutions and relationship development between Temo, Socoyote, and Ollin after the tournament.

I think this was a really well developed story and I am so glad I got the opportunity to read this early!

[Sky · Rating 5 out of 5]

Thank you to Sonido and Harper Collins for a free ARC! All opinions are my own.

Representations: https://trello.com/c/pOIW0Wsu

No matter what gets taken from us. no matter how much of our past or how many of our people get killed, we persist. We will always persist.

Characters were all so strong. There is pretty constant PoVs swapping between quite a few people, but it never felt terribly confusing, even on chapters with no names on them. They all had a distinct style in the way each character thought and even nameless chapters had more than enough in the first couple sentences to work out exactly whose PoV it was.
The main cast was excellent, with a proper love triangle as well (with all 3 sides 😉). Temo was such a strong MC with loads of flaws but also such a strength about him. Flanked by Socoyote and Ollie the trio really grew into a really good cast with solid arcs, each of them bounced off of each other great. The side characters then also really shined, even the ones we barely get to see somehow.
I also just want to pick them all up and give them a hug - except the king and queen and all the assholes >.>

I'm absolutely obsessed with the world building and history of it all. The religious indoctrination and fascism, the rebels and it all comes together so well to make such an alive feeling world. There is a fair amount of telling about stuff in the world, but a lot can be gotten from Temo's internal thoughts. I think there's only one bunch of questions left and every single one is around Ollie. His story is detailed a fair amount, but there's still quite a lot of questions I have about most of him 🤔

It is pretty similar to hunger games specifically but even though I kept thinking about that I never wanted to stop reading this and go read hunger games instead. This has much more world building and a lot more going on in the world instead of the "mostly just America" of the hunger games (I say this as someone who absolutely loves hunger games, especially its political side). If you enjoy hunger games (the books) though I'd say almost certainly you'll also love this book.
Writing style certainly still reads YA like HG - the characters are teens, but it doesn't read like an adult writing kids. I would certainly say it's not for younger YA though, it's more brutal and graphic than the original HG trilogy at least by quite a lot.

[Owen Lach · Rating 5 out of 5]

Entering To Our Untamed Core by Sonido Reyes feels like stepping directly into a fighting arena. This high-stakes, brutal gauntlet of a novel demands your full attention from the opening moves.

Reyes pulls no punches. The religious trauma is visceral and unavoidable. Had I not read the content warnings beforehand, I might’ve tapped out in the first few pages. While the prose is highly accessible, the level of violence hits hard and might overwhelm younger readers.

Once you’re in, the world-building is spectacular. Comparisons to The Hunger Games and The Sunbearer Trials are apt, but Reyes has engineered a completely unique battlefield. The story skillfully blends sci-fi and alt-history, using the Afuereños to represent real-world civilizations fractured by Spanish colonization. Reading a sci-fi/fantasy story rooted in Mexican and Central American lore is deeply refreshing, especially with El Centro standing in as the villainous European colonizers.

The battles our characters face start well before El Torneo actually begins. Temo’s struggle to shed his religious programming and the terror of hiding his true identity from a hostile regime hit incredibly close to home. And Reyes ensures their trans-masc protagonist commands the spotlight. Seeing Temo serve as the central love interest for two rivals, Ollin and Socoyote, is a massive victory for queer storytelling. He’s the champion of his own narrative, securing the center stage he deserves.

To Our Untamed Core is a ferocious fight for identity and survival. With its unflinching exploration of religious trauma, spectacular world-building, and a trans-masc protagonist who fiercely commands his own narrative, Reyes walks away with another triumphant win.

[Lucky · Rating 4 out of 5]

Action-packed and thoughtfully chilling, To Our Untamed Core was an unflinching and heartfelt examination of colonial violence and the rebellion it necessitates.

As always, Reyes' character work is stunning and sincere. There is a broad cast, but they are all distinctive and beautifully fleshed out. Athziri in particular has my whole heart. The world building was also a triumph. The Afuereños, El Centro, the conceit of Spanish colonisation and religious abuse was executed with thoughtfulness and precision.

Some elements of the story felt unfulfilled, and I left wishing this were a duology. The plot's reliance on miscommunication and constantly shifting POVs were tiring. The pacing was generally solid, but weirdly rushed near the end. Reyes is cooking with some potent ingredients, and I feel they would have been better served with another book's worth of simmering.

If you are looking for a fast-paced YA dystopian with themes of anti-colonialism and a fabulous cast of characters, you are in the right place.

[Charles · Rating 5 out of 5]

I received an e-ARC and am giving my honest review. Thank you to NetGalley and the publisher for this opportunity!!

Oh wow. This was absolutely beyond good. I love Sonido Reyes’ books always, and this was such a new genre I was very curious to see how it would go. And wow. It was amazing. The best comparison I can see is Sunbearer Trials x Hunger Games, but this is wholly original and new in an absolutely incredible way. In a lot of ways, this was a lot darker than The Hunger Games was. There were moments that I stared at my Kindle with my mouth agape. But I loved it. Absolutely adored it. The cycling of POVs sometimes got a bit confusing/too much, but that’s a very minor complaint compared to how incredible this was. Although there are a lot of dark and mature themes, I would argue that this is the kind of book that should be required in high school classrooms. Creating a way to show how horrific colonizing is in a very new and “fresh” way for new audiences was absolutely genius. I can’t recommend this enough. Plus! A true love-triangle!!! Finally!!

[Lindsay · Rating 5 out of 5]

Rep: trans MMC, Mexican

I have loved every book Sonido Reyes has written, and To Our Untamed Core, their first speculative YA novel, was no exception. It's been marketed as the Mexican Hunger Games and didn't disappoint; it explores the effects of colonization and religious indoctrination. TOUC is told from multiple points of view, including our three main characters who are in a true love triangle. Temo knows once he turns eighteen that he’s destined to be sentenced to El Torneo, a tournament to the death and punishment for breaking society’s laws, because he’s hidden his identity as a trans male. He is determined to save his loved ones, including his estranged best friend Soyocote and his boyfriend Ollin, from a similar fate. The cutthroat, perilous setting starkly contrasts with the characters' determination to fight as a community and resist the narrative that they’re “untamed” and barbaric.

CW: colonialism, detribalization, religious indoctrination, violence, death, decapitation, cannibalism, infertility, plagues, death of a parent, poisoning, transphobia

[Kaye Johnson · Rating 5 out of 5]

This was, simply, awesome. "Chain Gang All Stars" meets "Hunger Games" meets "The Sunbearer Trials" meets the beautiful, thoughtful, fun writing of Sonido Reyes. Every character was developed so well I can't believe it. How Reyes can create such a complex world and characters with that much action happening is truly a feat. The care Reyes gave to Athiziri?? Don't get me started; I love that girl and I loved how she was cared for. As a Librarian this is such an easy recommendation for me. There is so much for anyone to enjoy.
I do think this will get compared too much to the Hunger Games, and while I understand it and I even compared it at the beginning, I want to stress that this book is so much more!

[Alechia · Rating 5 out of 5]

This book was incredible and compelling; I couldn't stop reading and was STRESSED the entire time. It's action-packed, emotional, and inclusive. I loved how we saw so many point of views, you get every side of this story, which makes it fully engaging, offers so much depth, and ups the stakes. You can't help rooting for Temo, Socoyote, Athziri, and Ollin as they deal with trauma, turbulence, family, and impossible odds. It's powerful, and the entire time I wasn't sure how it was going to end. The comparison to Hunger Games and Sunbearer Trials is legit, while being something wholly new. I love seeing Sonido in science-fiction and I can't wait to see more!!

[Hadley Morrison · Rating 5 out of 5]

Sonido Reyes, the storyteller you are!

Reyes is an auto-read author for me. Anything he writes, I’m going to read. So when I saw To Our Untamed Core was pitched as The Hunger Games (fave) meets The Sunbearer Trials (fave), I already knew this was going to become of my favorite books of 2026, and Reyes DID NOT DISAPPOINT!

Temo, growing up knowing that he will someday be thrown into the fight-to-the death that is El Torneo when it is discovered that he is trans, ends up escaping his fate only to join El Torneo anyway when his boyfriend Ollin is taken instead. He’s determined to save the ones he loves from their fated end. But everything he thinks he knows is shaken after a shocking betrayal!

[Aiden Thomas · Rating 5 out of 5]

Fierce, devastating, and achingly hopeful. "To Our Untamed Core" is a breathtaking rebellion story about love in all its forms and the brutal systems built to crush it. Sonido Reyes crafts a world of religious terror, stolen histories, and impossible choices, then fills it with characters so vivid and vulnerable you cannot help but fight beside them. A stunning, unforgettable fantasy about what survives when everything else is taken away.

[Chloe · Rating 5 out of 5]

This was absolutely everything a YA dystopian should be. Both tender and brutal, it doesn't shy away from the horrors of colonization, and how much it rips away from people. But it also doesn't shy away from hope, and from the understanding humans can offer, and the love that can still be found. It's brilliant.

[Spiri Skye · Rating 3 out of 5]

This was a bit of a mess for me. Still an enjoyable read, I really liked the representation & the love triangle(!!!) but I just feel like the villain was lacking in depth, half the plot was because of miscommunication, and there’s a lot of threads with no closure. I really like this author but just wanted more from this.

[Lexi · Rating 3 out of 5]

2.5 stars rounded up to 3. I think there were a lot of loose ends that needed to still be tied up. This story is so rich and has so much actual history involved it would have benefitted heavily if it was either longer or split into a second book. Overall this was a great first attempt at a new genre change by Sonido! I'm excited to see more books from them.

[BibliofiendLM · Rating 3 out of 5]

Look for my full review in School Library Journal.