The Empyrean series saw a major new release earlier this year with Onyx Storm, and now all three titles are dominating Amazon's Kindle bestseller list for 2025. The series initially gained widespread popularity after Fourth Wing debuted in 2023, largely propelled by BookTok. Since then, this romantic fantasy series has expanded its audience enough to consistently rank at the top of multiple bestseller charts.
The strong reception for Onyx Storm demonstrates the viral appeal of Rebecca Yarros' writing, which blends fantasy and romance in a way that captivates a wide range of readers. With a Fourth Wing television adaptation officially greenlit by Amazon, the Empyrean series has the potential to surpass even the popularity of the Harry Potter book franchise if future decisions are well executed.
Physical Editions Are Also Highly Popular
Onyx Storm (Deluxe Limited Edition)
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While the Empyrean series dominates Kindle rankings, it has also secured a place in Amazon’s top-selling print books for 2025. Both the deluxe and standard editions of Onyx Storm rank in the top 10, with Fourth Wing remaining in the top 25.
Only the recent release of Suzanne Collins' new Hunger Games title has pushed Onyx Storm to second place on the fiction chart. Still, with new readers continuing to discover the series through Fourth Wing, its position could shift again before 2025 ends.
Fourth Wing and Iron Flame Are Included in Kindle Unlimited
Kindle Unlimited
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The first two books in the Empyrean series are currently available for free on the Kindle app with a Kindle Unlimited subscription. To dive into the series, simply log into your Kindle account and download both Fourth Wing and Iron Flame before they are rotated out of the subscription catalog.
