The Empyrean series has made a significant impact with the recent release of "Onyx Storm" earlier this year, propelling all three books to the top of Amazon's Kindle best sellers list for 2025. The series' surge in popularity began with the publication of "Fourth Wing" in 2023, largely boosted by the influence of Booktok. Since then, this romantasy series has grown tremendously, consistently topping bestseller charts.

The release of "Onyx Storm" has attracted a wave of new readers, showcasing the viral appeal of Rebecca Yarros' storytelling. Her unique blend of fantasy and romance has captivated a wide audience. Furthermore, with the announcement of a "Fourth Wing" TV series in development at Amazon, the Empyrean series has the potential to surpass even the Harry Potter franchise in popularity, provided it leverages its opportunities effectively.
The Physical Editions Are Popular Too

Onyx Storm (Deluxe Limited Edition)
1. See it at Amazon 2. See it at Barnes and Noble 3. See it at Target
While dominating the Kindle charts, the Empyrean series also features prominently on Amazon's top-selling physical books list for 2025. Both the deluxe and standard editions of "Onyx Storm" are within the top 10, with "Fourth Wing" maintaining a strong position in the top 25. The recent release of Suzanne Collins' new Hunger Games book has temporarily pushed "Onyx Storm" to the second spot in the fiction category. However, with the growing number of readers discovering the series through "Fourth Wing," it's possible that "Onyx Storm" could reclaim the top position before the end of 2025.
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Fourth Wing and Iron Flame are Part of Kindle Unlimited

Kindle Unlimited
35. See subscription options. 36. See it at Amazon
For those looking to dive into the series, the first two books, "Fourth Wing" and "Iron Flame," are currently available for free on the Kindle app with a Kindle Unlimited subscription. Subscribers can access and download these titles before they potentially leave the subscription service.