Warning: SPOILERS ahead for Onyx Storm by Rebecca Yarros.Onyx Stormwas one of themost-anticipated fantasy books of 2025, but while theFourth Wingsequel received a lot of hype on the heels of its release, it also ran into the same problem as the Marvel Cinematic Universe’s Phase 4.Fourth Wingbecame one of themost popular books on BookTokafter its 2023 debut, and its sequels have stirred plenty of excitement within the book community. Sadly, the following twoEmpyrean Seriesbooksdidn’t quite reach the heights of the first one. And there were some notableproblems withOnyx Storm,as fun as it was to read.

WhileOnyx Stormboasts many of the strengths of its predecessors — from snarky dialogue to shocking twists — it attempts to expand the series' world in ways that don’t always benefit the book. Perhaps this will pay off in thenextEmpyrean Seriessequel, but as its own entity,Onyx Stormhas a number of shortcomings that mirror those of the MCU Phase 4. This explains whyOnyx Stormcurrently has the lowestGoodreads rating of the three books. Fortunately, there are still two installments left in the series, and they can learn from the MCU’s missteps.

Cover of Onyx Storm by Rebecca Yarros

The MCU Phase 4 Was Criticized For Being Too Messy & Not Cohesive

There Are Too Many Characters, Storylines, & World-Building Additions In Onyx Storm

Like the MCU Phase 4,Onyx Stormfeels a bit unwieldy at times, as the book introduces new world-building elements, attempts to flesh out more supporting characters, and combines a lot of different storylines. The various plotlines often feel meandering at times, with theFourth Wingsequel only getting to the meat of the story during the last third of the narrative. Before that, Violet and her friends spend much of their time seeking outAndarna’s seventh breed of dragonand Xaden’s venin cure. And the results of these missions are pretty underwhelming, at least in this book.

1 Conversation In Onyx Storm Completely Wrecked Its Entire Premise

Onyx Storm’s messy plotting created some plot holes and continuity inconsistencies, but one conversation wrecked its entire villain premise.

This feels similar to the MCU Phase 4, which attempts to start anew on the heels ofAvengers: Infinity WarandAvengers: Endgame.Unfortunately, this chapter of the franchise fails to match what came before, mostly because it introduces too many storylines and heroes and hardly offers any payoff. Four years afterShang-Chi and the Legend of the Ten Rings,viewers are still waiting to see Simu Liu’s hero in a sequel, especially after the movie’s post-credits tease. And the events of projects likeEternalsandMoon Knightare barely mentioned again.

The covers of Fourth Wing, Onyx Storm, Iron Flame, and a book with a fiery 4 on it

While Yarros is likely to bring her storylines together more quickly than the MCU, there’s no denying thatOnyx Stormtries to do too much in just one novel.

While Yarros is likely to bring her storylines together more quickly than the MCU, there’s no denying thatOnyx Stormtries to do too much in just one novel. The trips to the various Isle Kingdoms start to feel repetitive, andOnyx Storm’s endingthrowsa lotat readers in just 100 or so pages. Additionally, the novel adds so much world-building that’s barely touched on before, from all thenew details about the veninto the fact thatFourth Wing’s godsare real and involved in human matters. Together, all this starts to feel messy.

Onyx Storm by Rebecca Yarros angled to the side and a black background with smoke and orange question marks

Onyx Storm Felt Like All Setup For Another Story

It Builds Excitement In The Same Frustrating Way As The MCU

Onyx Storm’s meandering storylines aren’t the only thing it has in common with the MCU Phase 4.The thirdEmpyreanbook also feels primarily like setup for future installments, which is true of many of the movies and shows from Phase 4. While each of them has their own narrative, the MCU’s Phase 4 projects always dangle the concepts of bigger threats, new characters, and future team-ups in front of viewers. The worst part is, many of these teases don’t actually pan out, likeWandaVision’s White Vision or the introduction of Kit Harington’s Black Knight.

10 Biggest Questions We Have After Onyx Storm’s Ending

Onyx Storm ends on a cliffhanger, just like the previous two books, and the newest Fourth Wing sequel raises many big questions in its final chapters.

This strategy of building excitement for the next project gets old quickly, and it makes many of the MCU’s Phase 4 projects feel unfinished.Yarros utilizes the same frustrating approach by leaving so much open-ended inOnyx Storm, attempting to build excitement by not tying much of the story up. This is expected to a certain extent in an ongoing series, but this sequel doesn’t feel like its own contained narrative nearly as much as it should.

Onyx Storm by Rebecca Yarros book cover pink background

Onyx Storm Relied On Too Many Characters No One Cares About Yet

This Meant Less Of Established Characters Like Rhiannon & Sawyer

Another thingOnyx Stormhas in common with the MCU Phase 4 is its reliance on characters that no one cares aboutyet — or at least not enough to justify giving them so much page time. On the heels of Iron Man’s and Captain America’s departure from the franchise, Phase 4 introduces too many new players, trying to make them feel like the new Avengers without organically getting viewers to care about them. This backfires, as it’s difficult to look forward to a team-up or get invested in the continued story when the characters aren’t fleshed out well.

19 Onyx Storm Characters You Might Not Remember From Previous Books

Yarros' world-building continues to expand from novel to novel, and there are several side characters who are reintroduced throughout Onyx Storm.

AndOnyx Stormalso introduces new subplots with supporting characters no one is really invested in. Even an unlikable newcomer like Halden gets his own frustrating storyline, and previously underutilized players like Lewellen are given a fair bit of attention. Sadly, this comes at the expense of page time for established characters readers already love.Rhiannon and Sawyer feel sidelined throughoutOnyx Storm, and even characters like Imogen and Bodhi don’t get the attention they deserve, especially given their importance to the story.

Fourth Wing, Iron Flame, Onyx Storm book covers dragon background

The Empyrean Series Book 4 Can Learn A Lesson From The MCU

It Needs To Refocus On What Readers Loved About Fourth Wing

The Empyrean Seriesis repeating a lot of the MCU Phase 4’s mistakes, but with two installments left, it’s not too late to learn from the superhero franchise. These complaints about the MCU resulted in many of its Phase 4 and Phase 5 projects doing poorly. AndMarvel has since decided to reduce its outputand focus its energy on specific, strategic projects in the hopes of returning to its pre-Phase 4 glory. The jury’s still out on whether it will succeed, butThe Empyrean Seriesbook 4 can take a similar approach toOnyx Storm’s biggest issues.

For the nextEmpyrean Seriessequel to reverse course and return toFourth Wing’s level of success, it should refocus on the main narrative and most important characters.

The Avengers in Endgame poster

For the nextEmpyrean Seriessequel to reverse course and return toFourth Wing’s level of success, it should refocus on the main narrative and most important characters rather than continue to expand. Readers are invested in what’s happening with the venin, Violet’s core circle of friends, and Xaden, and that’s where the next sequel’s attention should be. There’s no reason to double down on adding more lore and characters, especially if it takes away from what people want more of. Hopefully,Onyx Stormsends that message and its sequel delivers accordingly.

Onyx Storm Book Cover