Who Xaden's Venin Brother Really Is Gets A Major Clue From Rebecca Yarros In Threshing Day

Published Oct 18, 2026, 8:31 AM EDT

James Hunt is a writer and editor based in Newcastle, UK. A Sports Journalism graduate from the University of Sunderland, he quickly realized that supporting his local football (or "soccer") team, Sunderland AFC, was painful enough without having to write about it, so decided to write a load of nonsense about movies and TV instead.

Rebecca Yarros' new book, Threshing Day, provides more clues as to the identity of Xaden Riorson's venin "brother" as we await the next book in The Empyrean Series. Fans of Fourth Wing were left floored by the ending to Onyx Storm, which, among its many twists and turns, revealed that another character had chose to turn venin, and it's someone Xaden is at least pretty close to.

Only a few clues are provided about who Xaden's new brother is in Onyx Storm, but it's someone who had known for months that Xaden was venin, and someone he never expected would turn. That led to a few popular theories, with Bodhi Durran and Garrick Tavis, the two people closest to Xaden in the three books (aside from Violet Sorrengail herself), the most common, plus a few less obvious ones, such as Brennan Sorrengail or Aaric Graycastle.

The events of Threshing Day are set prior to Onyx Storm - there are 13 point-of-view chapters, which take place either before Fourth Wing, during it, or during Iron Flame - so there's no confirmation or major spoilers for the next Fourth Wing book. There are, however, clues, and while everyone will have their own theory (and there's no doubt an element of confirmation bias at play), I think it makes Bodhi being the brother more likely.

Threshing Day Makes Bodhi Being Xaden's "Brother" More Likely

Both Xaden and Bodhi have POV chapters in Threshing Day, and they're each important in the other's — but Xaden is much more so in Bodhi's. That's not only because he has a role in his cousin bonding with his dragon, Cuir, but because he dominates the thoughts of Bodhi so much. A lot of his chapter is spent comparing himself to Xaden, and focusing on how he's so much lesser than his cousin.

The Empyrean books had already suggested this was the case, but being inside his head makes it clear exactly how Bodhi views himself. With that in mind, and combined with the fact that Yarros herself has referred to him as being like "Xaden's shadow," it wouldn't be a surprise to see him turn venin after Xaden already has.

Threshing Day also puts a major emphasis on what happened to Bodhi's parents, and his vow that he will never again be powerless. This is a core part of his bond with Cuir, and it's interesting when combined with previous comments from Yarros, who had told readers to pay attention to who feels "useless" and like they aren't enough. Well, Bodhi's countering signet doesn't work against the venin in Onyx Storm, and if he vowed to never be powerless again, that might have played into his decision to turn, perhaps thinking it'd give him a better chance of defeating them.

Then there's something Cuir says towards the end of Bodhi's Threshing Day chapter: "I will choose you every day until your death or demise." Bodhi is confused by this, thinking they're the same thing, so the inclusion of this line is particularly telling. If there's the potential for demise to mean something different, something that would threaten the bond with his dragon, but isn't death, turning venin would be the one thing to fit. Bodhi also states that Durrans never break their promises, which feels like setup for a poignant moment of doing exactly that.

It isn't just Bodhi's chapter that makes me more convinced he's the brother, though, but also Garrick's. He's been the other big contender, though it's not a theory I've ever been as convinced by, and Threshing Day reinforces that view for one reason: Imogen. It already seemed unlikely he'd leave her alone in Onyx Storm after everything that happened, but after reading an entire chapter about how in love with her he is, and how he has been for over a decade already, I refuse to believe there's any way he'd do it.

Finally, it's worth pointing out the repeated use of the word "brother" in Liam Mairi's chapter. It's used five times in just a few pages, always in reference to his and Xaden's relationship. There are theories that Liam is still alive, and that he turned venin at Resson, and if you're someone who believes in that, then this may well bolster those views. I just also hope you're dead wrong.

We'll have to wait for the next Fourth Wing book to be sure on who Xaden's venin brother is, but I do think Bodhi makes the most sense. He cares far more about protecting Xaden than he does being heir to Tyrrendor, which would fit with this and also explain why Xaden and Violet got married. He shows time and again he hates being told what to do and does the opposite. And while it might be deemed obvious, that's because it's so deeply setup in his character arc, and it makes sense to see that through after Threshing Day.