Warning! Spoilers for Rebecca Yarros' Onyx Storm are below.The ending of Xaden's new venin brother, and what will happen to Xaden now that he's an asim. Knowing there's likely a two-year wait before the next Fourth Wing book will arrive, fans will have to rely on Yarros' clever foreshadowing to discover what potentially comes next.

After the release of both Fourth Wing and Iron Flame theories emerged online in quick succession—as readers attempted to find every clue Yarros left behind. Onyx Storm is no different, and only a week after its release, readers have begun to theorize what will happen in the fourth Empyrean Series installment. While there are several convincing theories, this list refers to those that are ed by direct quotes or common themes found throughout Onyx Storm's narrative.

10 The Isle Kingdoms Were Drained Of Magic By The Venin

Violet Describes Their Pale Color & Muted Tones

The Isle Kingdoms are a big part of Onyx Storm's narrative, and Yarros spends a lot of time exploring the new territory throughout the book. During Violet's quest squad mission to find Andarna's seventh den of dragons and secure allies for Navarre, she repeatedly observes that the isles look almost drained of color—but not completely. When they first arrive in Deverelli, this is one of the first things Violet notices, detailing that the grass, plant life, and trees are all muted or lacking in color.

"All of it is the same muted green as Deverelli."

—Onyx Storm, Chapter 29

The land in the Isle Kingdoms is suspiciously similar to Navarre's lands that have been desiccated by the venin—drained of color, the same way Navarre's is drained of life. While Violet's observations could be brushed off due to the varying climate and weather in the isles, it's possible Yarros is using the detailed repetition of muted color to hint that the venin were once present. The muted tones suggest that the lands were once drained of life, but if this happened hundreds of years in the past, the earth may have had the chance to grow again.

9 Violet’s Hair Is Now Completely Silver

Brennan Looks At Her Strangely At The End Of Onyx Storm

The end of Onyx Storm features one of Yarros' specialties—a completely unexpected plot twist and major info dump. So much happens and is revealed in the last few pages, but one detail that has caught most readers' attention is the way Brennan is staring oddly at Violet. As pointed out by popular BookTok creator @emmahalbrook, when Brennan first runs out to Violet in Aretia, his eyes immediately bulge as he looks her over for injury—noticing something peculiar about her appearance. This is again reaffirmed by the officer who runs out with Brennan, who also darts his gaze over Violet.

After Brennan reassures the officer that whatever it is they noticed about Violet is fine, they begin to reveal what happened after the battle. It's later during this scene that Brennan clocks Violet's ring, meaning this was not the detail he was shocked by earlier. This has convinced several readers that Violet's physical appearance is now different, and leads to the theory that suggests her hair is now completely silver. Knowing her and Xaden got married in Dunne's temple, it's possible she completed her dedication—which would alter her hair color to resemble those of the temple priestesses.

8 Tairn & Sgaeyl Broke Their Mating Bond

Andarna Could Be The Key To Breaking Bonds

Onyx Storm's ending reveals that Xaden is gone and won't be returning—and not only does this concern readers as to what this means for Violet and Xaden, but for Tairn and Sgaeyl. Iron Flame details how a mated pair of dragons can't be parted for too long due to their strong mating bond. But, now that Xaden and Sgaeyl have left and are not expected to return any time soon, theories on Reddit suggest that Tairn and Sgaeyl's mating bond is broken.

"So end it." He angles his head, and the scales above his eyes furrow into a single line. "Bonds are merely magical ties. You are irid. You are magic. Bend it, shape it, break it as you see fit."

—Onyx Storm, Chapter 53

There are several moments throughout the end of Onyx Storm that this theory, but one of the more convincing is knowing Xaden and Sgaeyl's plan for the future involves needing Tairn's agreement. In the final chapter, Violet notes her bond with Tairn feels foggy, almost like he's asleep. Andarna then tells Violet that Tairn needs a cycle of rest to recover, but readers are not clued in as to why. This has spurred theories suggesting Andarna—who Leothan says has the power to create or end bonds—broke Tairn and Sgaeyl's mating bond in order to keep Violet safe.

7 Violet Will Become Pregnant In The Fourth Empyrean Novel

There Are Several Moments That Foreshadow This

The idea of heirs is a reoccurring topic throughout Onyx Storm. But while it's never really discussed in relation to Violet and Xaden's relationship, instead it is suggested Xaden will eventually need to secure an heir for the future of Tyrrendor. Aside from this, the strongest argument for this theory actually comes from a statement given by the Irids. After the Irids first find Andarna and begin to question her, they broach the topic of the venin in hopes of finding a cure. The Irids state there is no cure, but mention that "their offspring could evolve".

It's possible that his love for Violet, and their future child, would help to cure him—or at least keep part of his soul intact.

The idea of Violet and Xaden having a child never really made sense until the Irids comment about venin offspring. It's known that when humans become venin, their souls die—leaving behind a dark wielder with no emotion. But Xaden seems to be different from the others, and is seen in his final chapter holding on to his tether to Violet with everything he has. It's possible that his love for Violet, and their future child, would help to cure him—or at least keep part of his soul intact.

6 Brennan’s Rune Scar Is Definitely Tied To Naolin’s Venin Powers

Sloane's Siphoning Signet Doesn't Leave A Mark At All

Violet first notes Brennan's rune-shaped scar in Iron Flame, and immediately comes to the conclusion that it must have been a result of Naolin using his siphon signet to save Brennan's life. However, in Onyx Storm, Sloane siphons power from Dain into Brennan in order to save Mira and no scar is left behind. Violet also notices this peculiar moment but has not yet had time to ruminate on what it means.

"Weird. There's no mark at the back of his neck like he carries on his palm. There hadn't been one on Dain's wrist, either."

- Onyx Storm, Chapter 59

Knowing that using a siphoning signet to imbue or power up another's signet does not leave behind a scar is incredibly suspicious. And the only real explanation would be that Brennan's scar—as mentioned in an earlier Onyx Storm theory—is actually a result of Naolin's venin powers. This hinges on the theory that Naolin is in fact a venin, and the rune he left on Brennan's hand acts in a similar manner to the runes that control the venin-made wyvern. This also suggests that Naolin could be using Brennan as a spy—whether he's aware of it or not.

5 The Irid’s & The Venin Are Somehow Related

They Can Sense Xaden Is Venin Without Him Wielding

When the Irids find Andarna and Violet on the isles, they are quick to show their disinterest in Navarre's impending war with the venin—even going as far as to say that the corrupted ones should devour the land in its entirety. From their conversation, it's clear they think the venin are abominations—but their lack of concern for their life-draining power is incredibly suspicious. As a species that values peace, it's curious they would even be okay with the venin draining an entire continent full of power.

There's also a moment when Xaden arrives that his eyes glow red in the presence of the Irids. No other dragon has been able to tell Xaden was venin, but for some reason, the Irids can feel his presence and can reveal his eye color without him needing to channel. It's possible that the Irid and venin magic are tied together in some way—especially when noting that both the venin and the Irids disappeared from Navarre in tandem as a result of the Great War 600 years prior.

4 Bodhi Is Xaden’s New Venin Brother

His Character Arc Makes Him The Most Likely Option

Bodhi holds a much larger role in Onyx Storm than in previous Empyrean Series novels. And it's through his character arc that many are convinced Bodhi is Xaden's new venin brother. For one, Xaden notes that whoever this new brother is, has watched Xaden struggle with becoming venin for over five months, and is confused as to why they would choose it for themselves, knowing what they do. This narrows it down to only two people; Bodhi or Garrick. However, Bodhi's character arc throughout Onyx Storm makes him the more likely of the two.

Throughout the novel, Bodhi, while being incredibly powerful, is kept out of harms way because he's second in line to rule Tyrrendor. This is clearly a role Bodhi has never wished to hold, and he's obviously irritated with Xaden for leaving him out of several plans to fight. This is also seen when Violet forces Bodhi to leave when fighting Theophanie. While he was supposed to have returned, Imogen's POV notes that Bodhi is still around, and is seen getting sick on his hands and knees. But the most convincing detail is that Xaden left Tyrrendor to Violet—likely due to the fact that Bodhi was no longer an option.

3 The Venin Are Attempting To Build An Army Of Wielders Akin To The First Six

They Are Targeting Those Deemed The Most Powerful Wielders

From the very beginning of Onyx Storm, Yarros reveals that both Xaden and Violet's signet abilities have been used in tandem to fight the venin once before. But, they are also the first of their signets to live simultaneously since the Great War over 600 years prior. Both Fourth Wing and Iron Flame have already reinforced the idea that Violet and Xaden's signets are the strongest, but an epigraph from Chapter Two of Onyx Storm reiterates that their signets are two of the six most powerful to ever walk the continent simultaneously.

The rarest of signets—those that rise once in a generation or century—have manifested concurrently with an equal twice in our records, both critical times in our history, but only once have the six most powerful walked the Continent simultaneously. As fascinating as that spectacle must have been, I would rather not live to see it happen again.

—A Study On Signets by Marjor Daltaon Sisneros

Considering the fact the venin have so far been entirely obsessed with Xaden and Violet, it is theorized that the venin are aware of the six most powerful signets, and are preparing to capture and turn each one. The venin now have Xaden completely in their grasp, and Yarros has made it clear from the beginning that the venin want Violet's signet as well. However, the remaining four signets are still kept under wraps—but it's possible that Garrick's distance wielding and Imogen's rock wielding could be targeted next—as their signets have not been seen in centuries.

2 Dain & Sloan Have A Future Romance Arc

Their Characters' Relationship Parallel's Violet & Xaden's

There are only a select few moments in Onyx Storm that point to this, but Dain and Sloane's minimal interactions seem to be dripping in romantic tension. While Dain and Sloane never truly interact in Iron Flame, it's made known that Sloane despises him, as she blames him for the death of her brother. However, Onyx Storm hints that there might be more to their relationship than meets the eye. In Chapter 28 of Onyx Storm, Violet catches an odd look on Sloane's face—one she interprets to mean Sloane wants to either stab Dain, or is painfully yearning for him.

Sloane is reluctant to use her powers after she killed Violet's mother at the end of Iron Flame, but Dain is surprisingly both stern and gentle in his encouragement to use her powers.

This theory is later reinforced when Sloane and Dain fly into Draithus and help save Mira. Sloane is reluctant to use her powers after she killed Violet's mother at the end of Iron Flame, but Dain is surprisingly both stern and gentle in his encouragement to use her powers. But one line from this interaction has fans reeling. After Sloane states that her powers will hurt Dain, he responds with "Gods, don't I know it". Their potential relationship also mirrors Violet and Xaden's in early Fourth Wing, beginning as enemies who just can't keep away from each other.

1 Aaric Knows How He Will Die

His Precognition Signet Shows Him The Future

Aaric's signet in Onyx Storm was completely unexpected, but after Yarros revealed it to readers, several moments throughout the book began to make sense. Aaric's precognition ability has yet to be explored in great detail, but it's assumed from a few moments throughout the book that he can see a certain number of hours into the future. This is showcased when he orders Violet to protect Dunne's temple, and when he sends Sloane to deliver the weapon to kill Theophanie and save Mira. But, it's possible his precognition signet allows him to see further into the future than previously believed.

"I will fight in this war, most likely die, and do so knowing that I protected others."

—Onyx Storm, Chapter 36

However, there's one line in Onyx Storm that has led readers to believe that Aaric has seen his own death—and proves he can see further into the future than a few hours. During a conversation between Aaric and the rulers of Hedotis, he states that one day his brother will become king—albeit a bad one—and explains that if he dies in the war, at least he did so in service of protecting others. Before knowing his signet, this line doesn't hold much weight—but after, it clearly hints at Aaric's possible future in the next Fourth Wing novel.