Product guide

Once Upon a Demon's Heart (Deluxe Edition)

Edition: Once Upon a Demon's Heart is a deluxe romantasy by K.M. Moronova, featuring an arranged marriage between a demigod knight and a demon commander. Its war, recurring curse and enemies-to-lovers premise may suit readers drawn to high-stakes fantasy romance.

At a glance

Fantasy romance centres on Alira, a demigod knight, and Kalel, a demon commander she once tried to save.
The plot combines a peace marriage, a curse that repeatedly sends Alira through her kingdom's destruction, political danger and a history of vengeance.
Deluxe edition listing specifies printed edges, a full-colour printed case, full-colour endsheets and spot gloss.

Price

$36.10Save 20%

Reference price: ~~$44.99~~

Price checked: Nov 14, 2026

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Often bought together

Once Written in Gilded Blood (Deluxe Edition)

$42.61

Bulletproof (Deluxe Edition)

$28.41

Pros and cons

Pros

The arranged-marriage and enemies-to-lovers setup gives the romance a clear conflict tied to the war and the characters' shared past.
The deluxe edition's printed edges, colour case and endsheets add decorative print features.

Technical specifications

12 specifications

Book details
Publisher	Sourcebooks
Publication date	June 23 2026
Language	English
Print length	336 pages
ISBN-10	1464279012
ISBN-13	978-1464279010

Format and dimensions
Dimensions	13.97 x 2.77 x 20.96 cm
Weight listed	386 g

Deluxe edition features
Printed edges	Printed edges
Case	Full-color printed case
Endsheets	Full-color endsheets
Finish	Spot gloss

What to know before buying

The listing describes a violent war, a massacre, repeated deaths, assassins and a curse, alongside romantic and emotionally intense themes. Consider these elements if you have content sensitivities.

Who is it for?

A good fit for

Readers seeking fantasy romance with an arranged-marriage and enemies-to-lovers storyline.
Readers interested in a war-and-gods setting, a recurring curse and an emotionally intense romance.
Collectors who value printed edges and colour printing in a deluxe edition.

Less suited to

Readers looking for a light romance without war, violence or recurring death themes.
Readers who prefer character development that is less divisive among readers.

Customer reviews on Amazon

4.3 / 5 · 8,079 ratings

5 stars52%52%
4 stars30%30%
3 stars15%15%
2 stars3%3%
1 star0%0%

Customer feedback highlights an engaging, emotionally affecting story, with readers also mentioning the romance's spice and the tortured-soul elements. Some report finishing quickly and wanting to continue the story. Opinions on character development are mixed, with praise for the yearning between the leads alongside criticism of the character building. For readers choosing this as a romantasy, that feedback suggests the emotional relationship is a draw, while characterization may be more subjective. The overall rating distribution leans positive, but it does not establish why individual readers rated the book as they did.

Positive themes

Readers describe the story as beautiful, captivating and engaging, with emotional elements that resonate.
Some readers praise the yearning between the main characters and the romance's spice.

Mixed feedback

Opinions on character development differ. Some readers enjoy the leads' yearning, while others find the character building weak.

Frequently asked questions

What is Once Upon a Demon's Heart about?

Demigod knight Alira volunteers for a peace marriage to Kalel, a demon commander who is also the boy she once tried to save. Their union unfolds amid war, a curse, assassins and a difficult history.

What deluxe edition features are listed?

The listing specifies printed edges, a full-colour printed case, full-colour endsheets and spot gloss.

How long is the book?

The listed print length is 336 pages.

What do customers say about the story and characters?

Customer feedback describes the story as engaging and emotionally affecting, and some readers enjoy the yearning between the leads. Responses to character development are mixed.