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"There's so much more to discover before the world ends."

Sylens is the deuteragonist of Horizon Zero Dawn and a returning character in Horizon Forbidden West. He is a wandering traveler and researcher, and the founder of the Eclipse. He has a deep fascination with the history and technology of the Old Ones, and allies with Aloy to discover the truth behind the machines and the fate of the Old Ones.



Sylens’ past is shrouded in mystery and stained with treachery. All that is certain is that at an early age, he became fascinated with the Old Ones, and dedicated his life to uncovering their secrets, especially what happened to them.

In his early adulthood, he came to Ban-Ur alleging to be the shaman of a remote werak known as Owl’s Watch. With his unrivaled knowledge of machines, he quickly gained the trust of the Conclave, who gave him knowledge of Malmstrom, their most sacred meeting place. Sylens was last seen by the Conclave at Malmstrom during their customary meeting at high winter. When the Conclave returned for their next meeting, they found the caves looted and Sylens missing. None of the trackers sent after him returned, and the people in Owl's Watch who claimed him as their shaman had vanished, leaving no trace of Sylens's existence. Deeming his actions a sacrilege, and doubtful that he was even Banuk to begin with, the Conclave declared an oath of secrecy surrounding any matters regarding Sylens.

"Hmm. I've heard that name once or twice. But always whispered, like some boogeyman the Banuk want to forget."

Sylens was the first to explore the GAIA Prime ruins following its self-destruction, although he was unable to venture far into the facility without the required clearance and settled for establishing a workshop at the ruin's edge.

Discovering HADES

A defining moment came when he discovered a heavily damaged Focus in an ancient ruin.[1] After spending weeks repairing it, Sylens detected a faint signal. Curious, Sylens followed the signal to the jungles of the Jewel, where he found a buried and shattered Titan containing the corrupted AI HADES.

Sylens repaired HADES to the point where it could speak, and thus a deal was struck between him and HADES: Sylens would serve HADES and teach it everything he knew about the new world (particularly regarding the Spire) and in exchange, Sylens learned about numerous academic fields, including physics, calculus, and computer science.

Creating the Eclipse

The Liberation and subsequent Carja Civil War was a welcome opportunity for Sylens; he arranged a meeting with High Priest Bahavas and the Kestrel Helis, the leaders of the Shadow Carja. Presenting HADES as the Buried Shadow of Carja lore, Sylens manipulated the Shadow Carja into creating the Eclipse, a cult to serve HADES and take back Meridian. On HADES's orders, Sylens found and repaired dozens of Focuses for the Eclipse army, and began creating a Focus network built to the AI's specifications.

While Sylens never trusted HADES, he did not question its motives until it began reviving ancient robots. Wary of its intentions, Sylens created a backdoor in the Focus network which allowed him to listen to all communications.

After Sylens completed the Focus Network, HADES decided that Sylens had outlived his usefulness and ordered his death. However, Sylens managed to escape, having overheard the kill order through the backdoor. Now a fugitive of the cult he helped create, Sylens was forced to go into hiding and monitor the Eclipse in the shadows.

Allying with Aloy

One night, Sylens noticed something peculiar on the Focus network: HADES issuing a kill order against a Nora girl named Aloy. Sylens was initially perplexed as to why HADES deemed a Nora savage a threat, but then noticed Aloy's Focus, as well as her uncanny resemblance to Dr. Elisabet Sobeck, a renowned scientist from the Old World. Upon confirming that Aloy survived the Proving Massacre, Sylens began observing her through her Focus. The longer he watched, the more he realized that Aloy was the key to finally learning the secrets of the Old Ones.

He made his first introduction to Aloy by contacting her Focus, but did not reveal his name, and helped her to disable Eclipse Focuses as she tried to confront Olin. Sylens contacted her again when she was directed to the ruins of the corporate headquarters of Faro Automated Solutions, providing her with a supply crate and some datapoints to help her better understand the building. Through Aloy, Sylens learned about the Faro Plague, confirming his suspicions that Faro robots destroyed the Old Ones' civilization; and Project Zero Dawn, the countermeasure created by Sobeck. When Aloy voiced her frustration about not finding the answers she wanted, Sylens scolded her for whining when she had discovered more in minutes than he had in decades of searching. He made a proper introduction via hologram and helped redirect Aloy, arguing that her own mystery was part of a larger web of secrets, all tied to Aloy's connection with Sobeck. The two quickly agreed that investigating Project Zero Dawn would provide both of them with the answers they wanted, and after answering Aloy's questions (albeit reluctantly), Sylens pointed her to Sobeck's last known location: the headquarters of U.S. Robot Command, now a ruin site known as the Grave-Hoard.

Within the Grave-Hoard, Aloy uncovered the location of the Zero Dawn Project Facility. Checking his data, Sylens confirmed that the facility was directly underneath the Citadel at Sunfall. The number of Eclipse agents with Focuses at the Citadel would make HADES finding Aloy almost certain, at which point the Eclipse and entire Shadow Carja military would be sent after her. At Aloy's suggestion, Sylens pointed the Nora Brave to a weak point in the Focus network which would allow her to crash it, slowing down the Eclipse dramatically. Once Aloy arrived, Sylens gave her the specifics of the task, including that the weak point was inside the Eclipse's base. Aloy quickly deduced Sylens had been part of the Eclipse. Sylens admitted to "assisting" the Eclipse, but refused to elaborate further. After Aloy destroyed the device powering the network, she confronted Sylens over leaving out that HADES would be present at the Eclipse base.

Sylens speaks with Aloy after saving her from the Sun-Ring

In the Zero Dawn facility, Aloy and Sylens learned of the project and its goal of recreating the world after the Faro Plague. Eventually, Aloy arrived at Elisabet's office and downloaded the Alpha Registry needed to enter the facility in All-Mother. However, the Eclipse entered the facility and Aloy was captured by their leader, Helis.

Knowing that he would never learn the secrets of the mountain without her, Sylens decided to rescue Aloy. To that end, he overrode two Striders and three Ravagers and stormed the Sun-Ring, having anticipated that Helis would sacrifice Aloy in the Sun-Ring at high noon. Sylens escaped with Aloy on the Striders while the Ravagers engaged a pair of Corruptors that Helis ordered to kill the Nora Brave. In the process, Helis called Sylens a traitor, revealing his connection to the Eclipse. Once they were at a safe distance from Sunfall, Sylens provided Aloy with a new Focus to replace the one Helis destroyed, complete with copies of every datafile she scanned, including the Alpha Registry. Aloy then informed him that Helis had dispatched messengers to the Eclipse in the Sacred Land to massacre the tribe and asked for his help in stopping it. Sylens refused, having other matters to attend to. He then provided Aloy with a set of Shadow Carja armor to conceal her identity should she ever return to Sunfall. Before departing, Sylens apologized for being needlessly cruel regarding her origins.

Later, after Aloy fended off the Eclipse attack on the Nora, she finally gained access to the mountain, whereupon she discovered a message from GAIA, revealing that before her birth, an unknown data transmission turned GAIA's Subordinate Functions, including HADES, into self-aware entities and that she had to destroy herself to prevent HADES from wiping out all life. Furthermore, Aloy was revealed to be a clone of Elisabet Sobeck for the sole purpose of rebuilding GAIA and was instructed to find the Master Override in the ruins of GAIA Prime to purge HADES. While Sylens was amazed that the red-haired Nora was more important than he realized, Aloy was horrified by the revelation that she wasn't a real person. Sylens admonished her for wallowing in self-pity and told her to fulfill her destiny, instructing her to meet him at the Bitter Climb.

Sylens appeared again in the ruins of the GAIA Prime facility, revealing that he had been attempting to enter the facility for years but was never able to crack the door. Aloy is able to enter, however, and learns of Elisabet's sacrifice to save GAIA Prime from premature destruction as well as Ted Faro's destruction of the APOLLO project and his murder of the Zero Dawn staff. Upon learning of Faro's actions, Sylens expressed his contempt and lamented the waste of unfathomable ancient knowledge, as well as disgust at Faro's naive belief he was sparing future generations, retorting that Faro never saw the barbarity in the Sun-Ring. Sylens appeared in person for the last time as Aloy left the facility, revealing his past connections to HADES and the Eclipse. He specifically related HADES' inquiries regarding the Spire, which led Aloy to deduce that HADES intended to reawaken the Faro Plague to destroy all life on Earth. He wished Aloy good luck and departed after giving her a lance that would serve as a means of injecting the Master Override into HADES.

After Aloy stopped HADES from broadcasting his signal and reviving the Faro machines, HADES remained alive. Sylens, having apparently intended for this to happen, captured HADES in a mysterious lantern-like device. With HADES as his prisoner, Sylens revealed his intentions of discovering who awoke HADES in the first place:

"Hello, old friend. Remember me?
We've still so much to discuss, so much you never revealed.
Your Masters, for example. The ones who sent the signal that woke you.
Knowledge has its rewards, don't you think?
Well.. let's begin.
―Sylens (to HADES)

Forbidden West

"This job demands a certain degree of patience, doesn’t it?"
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Half a year later after the events of Zero Dawn, he left the known lands and went into the Forbidden West. During Aloy's time in the Forbidden West, Sylens seems to have begun working with the Regalla, a rebel faction of Tenakth, assisting them in overriding machines.[2]


"He's unscrupulous and dangerous. But also brilliant, skilled, and knowledgeable without equal."
Ourea describing Sylens

Sylens is a well-spoken and erudite intellectual, albeit reckless and relentless in his pursuit of knowledge. For all of his life, he has been obsessed with uncovering the origins of the machines and the fate of the Old Ones. When it comes to expanding his knowledge base and research, Sylens has few, if any ethical boundaries: he has no compunction with manipulating and exploiting others so long as he gets the answers he seeks. He views ignorance as a curse, and that APOLLO was the greatest gift the Old Ones left behind.

Due to his coldly logical character, Sylens places little value on human emotions, seeing them as obstacles towards achieving one's objectives. As a result, Sylens can be extremely blunt to the point of being deliberately callous. He was insensitive to the emotional turmoil that Aloy felt after realizing her own origins, only remarking that she had two mothers; a dead woman and a machine. Sylens has the tendency to be condescending, assuming that Aloy believed the Earth to be flat, only to be flustered when she showed otherwise.

He is an incredibly secretive man, only revealing information about himself when it is crucial, and otherwise insisting that his secrets are his alone. He warns Aloy not to investigate any further into his past. Beyond his love for secrecy, Sylens is notably taciturn, rarely speaking with Aloy unless he deems it necessary.

In spite of his negative qualities, Sylens is capable of seeing his mistakes, admitting that he was foolish to serve HADES. Additionally, while he initially views Aloy as mere means to an end, he slowly comes to respect her ability and care for her well-being. Furthermore, despite his coldly logical dismissal of the deaths that occurred in the Carja civil war, or indeed that occur in any tribal conflict, he abhors the senseless bloodletting that the Carja engaged in under Sun-King Jiran. More than once he referred to the Carja Red Raids and subsequent human sacrifices with disgust while speaking to Aloy, and scornfully implied that the Carja would one day resume the practice.

Skills and Abilities

  • Skilled Programmer: Sylens has an unrivaled proficiency in the usage of Old Ones technology. He was successfully able to create a network of Focuses, as well as a back door that he could use to monitor them undetected.
  • Polymath: Due to his interactions with HADES, Sylens is well-versed in a number of subjects. He is quite possibly the most intelligent human in the new world since the extinction of the Old Ones themselves.
  • Archaic Knowledge: Having studied the Old Ones for most of his life, Sylens has perhaps the most comprehensive knowledge of the Old Ones of any human alive. His knowledge includes the concept of corporations, ancient medical techniques, and some understanding of long-ancient languages. He was able to deduce that Faro robots had a role in ending the Old Ones' civilization, although he was unable to confirm it until Aloy came along.
  • Master Strategist: Aside from his wide array of knowledge, Sylens is a skilled tactician.
  • Skilled Hunter: While not as obvious as his intellect, Sylens is adept as a hunter, being able to take down a Corruptor on his own.
  • Tribal Knowledge: Sylens has shown himself knowledgeable in Banuk and Carja lore. He is versed in the Carja faith to the point that he could present HADES as the Buried Shadow. While it is unclear whether he was ever part of the Banuk tribe, his knowledge of Shamanism is vast enough to where he could pass as a shaman, if not be one himself.


  • If Aloy goes to Sunfall before finding Olin, Sylens will reveal himself and warn Aloy not to enter the city or risk revealing to the Eclipse that she survived.
    • Likewise, if Aloy enters Sunfall before destroying the Focus network, she will be able to enter to a certain point in Sunfall, but will not enter the palace, as she agrees that it is too dangerous.
  • At the start of To Curse the Darkness, Aloy pulled a pun of Sylens' name, to which he responded with actual silence.
  • In The Frozen Wilds, should Aloy uncover all possible information from CYAN after the main DLC line of quests, Sylens will contact Aloy to tell his own remark of the newfound knowledge. Depending on the player's progress in the main story, this could be their parting conversation.
    • The tone of the conversation differs depending on Aloy's knowledge of Sylens' past. If Aloy never presses Ourea to reveal Sylens' story, Sylens will part peacefully. Otherwise, Aloy will make a bitter remark on his treacherous past, and Sylens will retort by warning her not to delve into his past.



Banuk Characters
Chieftains AratakFW - KopilaiFW - White Teeth ChieftainFW
Shamans AujakFW - Brin - EnjukFW - KamutFW - Kutani - NaltukFW - OureaFW - Siluk - Sylens - Tikuk
Tribe Members Aluki - AnutaiFW - Ardik - IkrieFW - InatutFW - Kikuk - Kimik - LaulaiFW - LauvukFW - MailenFW - NaunukFW - Nulat - OpiliFW - Opitak - RuatukFW - RukulFW - SekuliFW - SignutaiFW - TataiFW - TulemakFW - Ukan - UmnakFW - UrkaiFW - YarikiFW
Lore Arnak - Banukai - Tektuk