Warning: SPOILERS ahead for Onyx Storm by Rebecca Yarros.Rebecca Yarros' Iron Flame's cliffhanger ending sent readers around the world on a quest to save Xaden. Both Fourth Wing and Iron Flame begin to tease readers about the inner workings of the venin and their ranks, but it isn't until Onyx Storm that Yarros reveals more about how they operate internally.

Yarros clues readers in to the unique nature of the venin in Fourth Wing by detailing their red eyes, spider-webbed veins, and enhanced magical abilities — but by choosing to wield forbidden magic, their abilities extend much farther than previously believed. In addition to wielding gravity, speed, and draining life from the earth and other living beings, the venin in The Empyrean Series share a unique relationship with one another. Onyx Storm touches on this, as well as what happens to them once they turn venin and why they are so hard to kill.

Venin Can Sense One Another

Xaden Confirms This In Onyx Storm's Early Chapters

From the beginning of Onyx Storm, Yarros details how the riders at Basgiath are tasked with the responsibility of hunting down any remaining venin and killing them. During their flight expeditions, several cadets, including Violet and her squad, have located and expelled a small number of on the heels of Iron Flame's ending battle. However, Xaden's personal kill count is much higher than the others. Violet notes that he has eliminated 17 of the 31 venin, finding and killing them himself.

Lower ranking venin, such as initiates or asim, can be tracked down in order to be trained by higher ranking venin, like Sages or Mavens.

This is explained during a conversation between Violet and Xaden that takes place in Onyx Storm's early chapters. Through some strange bond or magic the venin can wield, Xaden is capable of sensing other venin in the vicinity. This unique trait is how Jack Barlowe could sense Xaden was venin as well. In a scene where Violet is interrogating Jack, he confirms that lower-ranking venin, such as initiates or asim, can be tracked down in order to be trained by higher-ranking venin, like Sages or Mavens.

Higher Ranking Venin Can Hide Their Identities

Jack Mentions They Could Be Hiding In Plain Sight

While the venin possess the ability to track down other venin, Jack explains that a higher-ranking venin, such as a Sage or Maven, would be harder to recognize. Apparently, in the early stages of transforming into venin, initiates or asim are not as adept at hiding themselves in the same way a Sage or a Maven can. This makes it easier for them to be tracked down. This is not the case for a Sage or Maven, and according to Jack, they could be hiding in plain sight and neither he nor Violet would ever know.

"Initiates, asims—we're all traceable to one another, but the great hall could fill with Sages and Mavens and I'd never know. Neither would you."

— Jack Barlowe, Onyx Storm

Jack's comments suggest that the higher-ranking venin are able to completely disguise themselves — that they're capable of hiding even their most distinct traits, like their spider-webbed veins, red eyes, and graying skin, from the unsuspecting public. Such abilities would give the venin an easy way to hide themselves among Navarre's ranks, and Violet's conversation with Jack practically guarantees that they are.

Venin Can Develop Signets, Or Don’t Lose Them When They Turn

Their Powers Are More Developed Than Previously Believed

This is one of the biggest revelations throughout Onyx Storm, as those who turn venin can develop their own signet abilities, or even keep them in the case of riders. While this might seem to be exclusive to riders who have become venin — as is the case with Xaden — it is also possible for other venin to develop signets on their own. The silver-haired venin, Theophanie, for example, has the ability to wield storms. However, her background is not of a rider but of a Dunne temple priestess.

Theophanie's life before turning venin would not have gifted her with any magical ability, and it's clear her turning venin is what granted her the power to wield storms. However, there are instances where it seems possible for the venin to gain more than one signet ability, though Yarros has not yet confirmed if this is the case. This element of the venin's power completely changes the strategies Navarre will have to implement throughout battle. They'll now need to match the signet of a rider to the ability of the venin in order to balance the scales.

Only Venin Initiates Bleed

They Become Harder To Kill The Higher The Rank They Are

Violet and Jack's discussion at the beginning of Onyx Storm reveals alot about the venin. For one, it confirms that only venin initiates — the lowest venin ranking — can bleed. This comment, while never discussed in great detail, gives readers insight into the different stages of becoming venin. It's clear from their conversation that, once a venin progresses past the first level, they become more and more immortal. Venin have always been hard to kill, as they are impervious to dragon fire and traditional weapons, and they can only be killed through magically imbued alloy daggers or by Violet's lightning.

This could be used as a test throughout the later series on any captured venin or suspected venin spies—gauging their level of power and ability by determining their rank and ability to be killed.

However, lower-ranking venin, such as initiates, must be easier to kill. This can be seen throughout Onyx Storm, as Xaden is capable of getting hurt by traditional weapons and can bleed — proving he's still in the initiate stage of the venin transformation for much of the book. This could be used as a test on any captured venin or suspected venin spies, used to gauge their level of power by determining their rank and ability to be killed.

The Venin Are Ageless

They May Have Survived The War 600 Years Ago

Another major Onyx Storm revelation in regard to the venin is the fact that they do not age and are somehow immortal. This detail may come as a shock, but knowing how hard they are to kill, this plot development actually makes a lot of sense. There are several book moments that point to this, but the first is seen through Violet and Theophanie's conversation in Samara. During this scene, Theophanie questions Violet about Andarna, stating she's an Irid. When Violet becomes confused, she states, "Sometimes I forget just how short mortal memory can be."

"Astonishingly ageless. Hair as black as the day we married, but in place of the age lines I'd expected were bulging scarlet veins branching outward from her red-ringed eyes."

—The Resurgence of Evil, A Timeline, By Pierson Haliwell

This comment prompts Violet to understand the true nature of the venin, coming to the conclusion that they are immortal. Theophanie's dialogue also suggests she's been alive for a very long time — and if she knows of Andarna's kind, it's possible she was alive 600 years ago, before they disappeared. This idea of an ageless venin can also be seen in Onyx Storm's chapter 48 epigraph (included above), which quotes a survivor of a venin attack in 472 AU. They mention the venin, who they presumably knew personally, hadn't aged a day.

The Venin Have Bonds Between Ranks

Xaden Has A Mysterious Connection To The Venin Sage

Onyx Storm introduces plenty of new elements to the venin narrative, but one of the most shocking is that the venin can create bonds between ranks. This is most noticeable in Xaden's chapter towards the end of Onyx Storm, as Xaden recognizes he is incapable of killing Berwyn, the venin sage he fought at the end of Iron Flame. Whatever the magic of their bond, it protects Berwyn from being killed by Xaden. And Xaden even states he "could no more raise a blade to his throat than I could Violet."

However, this sentiment is also reinforced through earlier dialogue between Violet and Theophanie. In Samara, Theophanie is trying to get Violet to turn and train with her instead of Berwyn — claiming that if Violet was to train under him, she'd be chained to Berwyn and powerless to resist his orders. This suggests that his rank may hold power over lower-ranking venin, and those at his command would be incapable of disobeying any of his orders.

The Venin Feel Less Emotion As They Get Stronger

Their Souls Are Dead And Incurable

Throughout Onyx Storm, Violet continues to believe she can save and cure Xaden—but as he slowly wields more of the forbidden power running through his veins, it's obvious he's losing bits of himself in tandem. There are several moments where Violet recognizes the Xaden is being controlled by his venin nature, and the ice-cold look in his eyes continues to grow throughout the narrative. He can only be talked out of his trance-like state when Violet intervenes. These changes are later confirmed when the Irid leadership, Fourth Wing's seventh breed of dragons, track down Andarna in the Isle Kingdom.

After insisting Xaden's venin nature is an abomination, the Irid's confirm there is no venin cure. They claim that Xaden's soul is dead and lost forever, and say there is no known cure to bring a soul back from the dead. Onyx Storm also consistently describes Xaden's wish to no longer feel emotion and escape with the freedom of feeling no pain, guilt, or suffering. This is explored in more detail through Xaden's chapter, as he gives himself over to his venin nature and closes himself off from his feelings — and the only tether he has left is Violet.