After being pushed to the sidelines in Onyx Storm, these Fourth Wing characters are overdue for more time in the spotlight when Book 4 of The Empyrean Series arrives. While Onyx Storm successfully raised the stakes for Violet and Xaden – especially as Xaden’s venin affliction grew more urgent and the race for a cure intensified—it left some loose threads dangling. Despite broadening the series’ scope and deepening several arcs, the story offered little resolution for certain characters’ fates and left others feeling like they were treading water.
1. Dain Aetos
Onyx Storm Overlooks the Most Compelling Aspects of Dain’s Arc
Although Dain appears throughout Onyx Storm, much of his character arc is pushed to the sidelines—making it essential for book 4 to revisit and develop his journey. His evolution from a rigid, rule-bound cadet to someone more morally flexible marks a major shift from how he was introduced in Fourth Wing. However, Onyx Storm barely explores this transformation after the Quest Squad returns to Basgiath, with Dain mostly fading into the background until his brief return alongside Sloane to help Brennan heal Mira before the Battle of Draithus. His growth deserves more focus in the next installment.
2. Rhiannon Matthias
Book 4 Should Dive Deeper Into Rhiannon After Her POV Chapter
Rhiannon’s POV chapter in Onyx Storm offered a glimpse into a side of her we’ve rarely seen — and book 4 needs to build on it. Known for being the steady, logical anchor of the Iron Squad, Rhiannon has often served as the voice of reason, balancing out Violet’s more emotional, impulsive choices — a contrast Onyx Storm leaned into heavily. But with her own perspective briefly explored, readers saw layers of Rhiannon that could shift the squad’s dynamic entirely if given more space in the story moving forward.
3. Berwyn
Berwyn Deserves More Page Time To Evolve Into a Truly Memorable Villain
Although Berwyn was positioned as a significant threat in Fourth Wing and Iron Flame, Onyx Storm doesn’t give him enough page time to fully develop into the formidable antagonist he’s meant to be. His lone appearance—where he manipulates Xaden into becoming an asim during the Battle of Draithus—is certainly impactful, but it feels more like a teaser than a payoff. Mentions of his ruthless methods through Theophanie help build tension, but to become a truly memorable villain in The Empyrean Series, Berwyn needs far more direct involvement in the next installment.
4. Jesinia Neilwart
Jesinia Deserves More Page Time To Justify The Series’ Framing Device
Jesinia may be confirmed to survive The Empyrean Series, but her near-absence in Onyx Storm makes it all the more important for her to return in a meaningful way in the next book. The series’ framing device—revealing that Jesinia, as Head Curator of the Scribe Quadrant, translated Violet’s records—implies she plays a significant role in the larger narrative. However, her limited presence in book three weakens that structure. Bringing Jesinia back with more insight and agency would not only reinforce the framing device but also add a fresh, intellectual perspective to the unfolding conflict.
5. Sawyer Henrick
Sawyer Is Still The Most Overlooked Member Of The Iron Squad
Sawyer’s arc in Onyx Storm offered the most meaningful look at his character so far, but there’s still so much more the next book could explore. His journey to reclaim his identity as a rider after losing his leg in Iron Flame was both moving and empowering. For the first time, we saw Sawyer beyond just being part of the Iron Squad—his vulnerability, frustration, and strength were fully on display. It also helped forge a deeper bond between him and Violet, giving them a new level of connection that felt more personal than what we’ve seen with Ridoc or Rhiannon.
Hopefully, Rebecca Yarros has bigger plans for them in the next installment of the romantasy series.
