Family[]
Nyx[]
Nyx: Thanatos's mother.
Thanatos holds great respect for his mother and consistently shows deference towards her. To him, Nyx's word is law, not just for him but for everyone else as well. He can't even bring himself to get angry with Zagreus for commuting Sisyphus' sentence simply because he knows Nyx must have approved it herself. In fact, his unwavering belief in Nyx's words even leads to a quarrel with Zagreus, where he reprimands the prince for continuing to talk to Dusa, despite Nyx instructing him not to. This may have earned him the reputation of being a "momma's boy" among other Chamber subordinates.
It is implied that Thanatos doesn't handle criticism well and doesn't appreciate when others offer their opinions about the way he works. He doesn't take well to his mother's disrespect when she suggests that he's doing more than his fair share of work, even though it's hypocritical because both are helping Zagreus. They share similarities in that they both operate in the shadows, working against Hades to assist Zagreus, and he knows her well enough to understand that she rarely changes her mind on matters related to the state of the House of Hades.
As his mother and superior, Nyx encourages Thanatos to strive for excellence in his work due to its importance. He offers to help her with domestic matters, but she encourages him to continue helping in his own way.
Hypnos[]
Hypnos: Thanatos's younger twin brother.
Despite being twins, Hypnos and Thanatos have remarkably distinct personalities. While Hypnos is laid-back and carefree, Thanatos is efficient and focused. Thanatos finds his brother to be too distracted and finds his approach to work uninspiring, often describing Hypnos as inattentive and inefficient. He believes that Hypnos spends more time talking than working, and even when he delivers a quality report, Thanatos assumes someone else helped him.
On the other hand, Hypnos yearns to spend more time with his brother, wanting to rekindle the closeness they once had. His current interactions with Thanatos consist mainly of lectures on professional conduct and work ethics, which he finds tedious and exhausting. Still, he expresses adoration and affection for Thanatos, hoping for more of his attention — even if all he gets is a cold, disapproving look.
Thanatos, though distant, cares for Hypnos in his own way. He steps in when his brother is in danger of losing his job and is the first to notice his passion for writing letters. Believing that this may be a way to guide him, Thanatos gives him to-do lists to help him organize his day and improve his focus. Although he rarely admits it, he secretly acknowledges Hypnos's progress.
Hypnos harbors familial concerns about his relationship with Thanatos, wondering whether his brother truly cares about him or if disturbing his sleep is intentional. Although he does not care much about what others think of him, he does fear rejection from his twin. Hypnos cares deeply for his brother and knows him well enough to recognize how overwhelmed Thanatos is — even if he denies it or does not show it — and, in return, he offers Thanatos a chance to come relax with him and encourages him to relax with him, although this earns him a scolding.
Zagreus also plays a pivotal role in fostering a better relationship between the twins. He encourages Thanatos to be more compassionate towards Hypnos and points out how "cruel" he has been to his brother. Thanatos takes this advice seriously, making an effort to be less harsh with his brother, resulting in a gradual improvement in their relationship over time.
After Chronos attacked the House of Hades in Hades II, Hypnos narrowly escaped while Thanatos stayed behind. Since then, the twins have been separated, and Hypnos fell into a deep, coma-like sleep as a defense mechanism. Melinoë must use Dream Vapors to enter his mind, where she finds him reliving memories of the House before the attack, fixated on Thanatos and repeating his phrase, “No Escape,” hinting their minds remain connected through dreams of Death. Medea suggests that this is profoundly linked to Thanatos, with Sleep and Death as two sides of the same coin, their realms intertwined, and that Hypnos cannot return to his duties until his brother is by his side.
After Chronos frees everyone from the freezing including Thanatos and Melinoë manages to wake Hypnos, Nyx says that they are reunited, and that Thanatos is happy to have Hypnos back with him.
Charon[]
Charon: Thanatos's older brother.
Thanatos both fears and admires his brother. He tells Zagreus that Charon was already in the Underworld before Hades and admits that, despite being just the ferryman, the entire Underworld would stop without him — it simply wouldn't exist without Charon. Thanatos encounters Charon frequently but confesses that even he doesn’t fully understand the extent of Charon’s responsibilities.
However, when using Companion Mort against Charon, Thanatos greets him with an enthusiastic “Hail, brother!” He also occasionally mimics Charon’s battle cry, “Hraaaagh!” during friendly sparring, suggesting they have more in common than it seems and may have trained together in the past. This is further supported by the fact that both have wielded Zorephet, possibly passed down from Charon to Thanatos.
Nemesis[]
Nemesis: Thanatos's older sister.
As their respective jobs mean they're never meant to cross, Thanatos and Nemesis are not particularly close and given what Thanatos knows of his older sister, that suits him fine.
Moros[]
Moros: Thanatos's older brother.
As Moros was raised by the Fates and never visited the House, Thanatos has no relationship with his older brother.
Eris[]
Eris: Thanatos's younger sister.
Eris seems to have a tense relationship with her brother. Thanatos rarely mentions her and even hesitates to say her name. However, he does state that Eris and her children are among the main reasons he has so extra work.
The Fates[]
The Fates: Thanatos's older sisters.
Despite all being children of Nyx, Thanatos isn't close to—or even in contact with—his prophetic sisters, the Fates. He doesn't know them and even suspected Zagreus of being their agent after seeing him with the Fated List. Despite being their brother, Thanatos has never requested the List himself and thinks maybe it was never meant for him.
He questions their role, Keep only to themselves, somewhere, and wonders whether destiny is truly real or whether they're making all this up as they go.
The Keres[]
Thanatos's sisters
Thanatos mentions his sisters indirectly in a conversation about Achilles. Although they all deal with death, their roles differ: his sisters appear first for those who die violently, while Thanatos usually comes later, dealing with mortals whose deaths are peaceful, planned, or natural.
Oizys[]
Thanatos's sister
Momus[]
Thanatos's brother
Geras[]
Thanatos's brother
Philotes[]
Thanatos's sister
Chaos[]
Chaos: Thanatos's grandparent.
Thanatos doesn't know his grandparent. Nyx never told him about it, and he never asked.
House of Hades[]
Zagreus[]
Zagreus: Thanatos' colleague/childhood friend/potential lover
Thanatos and Zagreus share a bond that dates back to their childhood, both raised by Thanatos’s mother, Nyx. They share a deep bond despite their opposite ways and perspectives. Thanatos is severe and disciplined, while Zagreus is reckless and warm-hearted. Although hurt by Zagreus’s decision to leave the Underworld, Thanatos chooses to support him on his journey. Their connection runs deeper than mere colleagues in the Underworld, and depending on Zagreus’s choices, their relationship can evolve into something more profound.
When Zagreus decides to flee to the surface in search of his true mother without saying goodbye, he remarks, “I thought you might just run from me, did you not?” Thanatos responds coldly, “Well, if you won’t say it, I will. Farewell, Zagreus.” While Zagreus notices some dramatic flair in Thanatos’s reaction, he realizes that Thanatos isn’t genuinely angry with him. Instead, Zagreus’s actions have put Thanatos in a difficult position. On one hand, Thanatos chooses to help Zagreus behind Hades’s back despite his personal feelings for his closest friend, even if it means defying Hades and risking his position. Even when Hades discovers his complicity, Thanatos continues to support Zagreus.
Zagreus understands Thanatos well, being one of the few who can see through his rigid armor and aloof demeanor. In Zagreus’s eyes, Thanatos is a kind-hearted individual, albeit one who struggles to express it openly. Zagreus brings out Thanatos’s playful side, a facet few are aware he possesses.
Zagreus can eventually provoke a competitive streak in Thanatos, challenging him to see who can dispatch more enemies.
Zagreus also has the opportunity to help Thanatos improve his relationship with Hypnos by encouraging him to treat Hypnos better after admitting he had been unkind to him.
Despite being a close friend and confidant, Zagreus may still have difficulty getting Thanatos to open up completely. Among all the romance options, Thanatos is the most elusive due to his busy schedule. When pursued, Zagreus may struggle with Thanatos’s reserved nature, even though he knows Thanatos means no harm. The connection between them remains a mystery, Achilles speculates, even to Zagreus, possibly because of their respective roles representing death and life/rebirth.
Zagreus's Forged Bond with Thanatos is described as Undying.
According to the Book of Shadows, Thanatos and Zagreus share a close bond.
Megaera[]
Megaera: Thanatos' colleague.
Megaera and Thanatos are long-time coworkers and friends. They are connected through their shared frustration over being deceived by Sisyphus in the past, which created a strong bond between them. In the present, they also share a mutual, if reluctant, affection for Zagreus, often accompanied by exasperation.
If Zagreus chooses to pursue a romantic relationship with Thanatos, Thanatos reveals that Meg encouraged him to confess his feelings—showing the trust and openness between them. The same applies if Zagreus starts a relationship with Meg, suggesting mutual support.
Depending on the player's choices, all three can enter a polyamorous relationship. Both Megaera and Thanatos are comfortable with this dynamic.
At one point, Meg and Thanatos have a private conversation and come to an agreement. Later, Zagreus walks into his room and finds both of them waiting. Thanatos casually greets him, while Meg chuckles and asks why he’s so surprised—reminding him his room has no doors. Initially confused, Zagreus quickly realizes their intent as both smile at him. Meg encourages him to trust them more, noting that she and Thanatos have been close long before he was even born.
Hades[]
Hades: Thanatos' boss.
Hades holds Thanatos in high regard due to his unwavering work ethic and the precision with which he collects souls. Thanatos, like his boss, values maintaining order within the House and becomes the poster child for motivational posters in the administrative office.
However, unlike the unquestionable authority of his mother Nyx, Thanatos does not treat Hades’ directives as absolute. He is even open to bending or finding loopholes in them — a rare break from his usual strictness — in order to assist Zagreus, Hades’ rebellious son who constantly challenges the status quo.
Initially loyal to Hades and the House’s traditions, Thanatos gradually found himself torn between his duty and sympathy. He chose to support Zagreus in secret while continuing his regular duties, effectively maintaining a dual role.
This support fades once Hades discovers Thanatos’ involvement, straining what had been a previously respected professional relationship.
Cerberus[]
Cerberus: Thanatos' friend.
He used to take care of Thanatos and Megaera when they were very young. They still play with Zagreus from time to time.
Skelly[]
Skelly: Thanatos' colleague.
Although he’s not displeased, he is a fan of Thanatos and is very happy when Zagreus summons him during the body count contest between Thanatos and Zagreus.
After Skelly arrives at the entrance of the Underworld, it is implied that Thanatos helped him reach Zagreus.
Dusa[]
Dusa: Thanatos' colleague.
When Nyx fires Dusa for her supposed inappropriate work behavior, Thanatos, without questioning her, says he'll start ignoring Dusa if necessary and suggests Zagreus do the same. Later, he admits he didn’t actually want Zagreus to abandon his friend. When Zagreus asks if he minds his closeness with Dusa, Thanatos replies that there’s no need to ask — those are his own feelings. If he and Zagreus are in a relationship, it remains subjective.
Dusa often gets carried away thinking about Zagreus and Thanatos, imagining “the things they do together,” blushing in panic before her thoughts go further.
Achilles[]
Achilles: Thanatos' colleague.
As the Peaceful Death, Thanatos recognizes better those who lived more slowly. He mentions that he wasn’t the only death entity to bring Achilles to the Underworld, due to the chaotic life Achilles had. Achilles became another of Hades’ contractors, just like Thanatos. Achilles says they are not particularly close, but based on his observations, he can say that Thanatos is decent—just like Hades.
In the Codex, it is stated that Achilles strongly encourages the relationship between Zagreus and Thanatos.
Persephone[]
Persephone: Thanatos's queen.
Their relationship is only briefly touched upon. Thanatos suggests to Zagreus that one of his eyes may be from Persephone and notes that she was once regarded by everyone in the Underworld as an exemplary queen — including himself. As the son of Nyx, Thanatos doesn’t talk much about Persephone directly.
In the post-epilogue, Thanatos calls her intelligent and says he always thought Zagreus inherited that from his mother — though now he's not so sure. Persephone has always liked Thanatos and always thought he was well-groomed and everything, and she encourages his relationship with Zagreus. She even jokes that Zagreus has much better taste than she does.
Upon her return, Thanatos greets her, saying that everyone is happy about her return and offering to help her settle in. Persephone replies: "Ah, thank you, Thanatos! I’ll take you up on that if something comes to mind. But my, how you’ve grown! I heard you’ve been looking after my son!" Thanatos excuses himself due to other duties, and Persephone responds playfully: "I know how mortals hate to be kept waiting!"
Later, after Zagreus mentions how close they’ve become, Thanatos thanks her for the blessings. Persephone praises his dedication and tells them both to take care of each other.
Underworld Residents[]
Sisyphus[]
Sisyphus: The Tortured Soul.
The former king once tricked Thanatos to avoid his own death. Thanatos and Megaera both express disdain about it and admit they had to work harder during that time. This earned the ire of the god of Death, as well as many other gods of the Underworld. Thanatos' resentment still lingers, even ages later, and he continues to distrust Sisyphus despite the king’s reformed demeanor after punishment—and even with Zagreus' support.
When Thanatos finds out that Zagreus reduced Sisyphus' sentence, he exclaims that Sisyphus is a scoundrel and the only mortal who ever humiliated him. Still, he can’t question it if Nyx approved the decision.
Sisyphus refers to Thanatos as Hades’ henchman and claims that he once tricked him and managed to escape death. He asks Zagreus how things are going and wonders if Thanatos is at least a little less harsh toward mortals now.
Still, Sisyphus admits he prefers Thanatos’ “Peaceful Death” and has always liked him—saying that being welcomed by him was far better than being taken suddenly and painfully, which helped him not fear the end. Zagreus confirms that Thanatos isn’t as bad as people think. Sisyphus reflects that bringing death must be a lonely job, though he jokingly adds that Thanatos should try pushing a boulder someday. He admits Thanatos doesn’t care much for him, but confesses to Zagreus that he’s still down there for a reason.
Olympian Gods[]
Ares[]
Ares: God of War.
Ares and Thanatos both deal with death, but in different ways. Zagreus questions Thanatos about his relationship with Ares. Thanatos doesn’t appreciate the way Zagreus frames the question but says that he is professionally courteous with him.
Ares mentions that they are close, although he believes Thanatos brings mortals in too mercifully. Still, he holds him in high regard when it comes to the subject.
Ares sometimes tells Zagreus to send his regards to the god of death or simply asks if he’s doing well. He also supports the idea of Zagreus and Thanatos becoming a couple, saying Zagreus has chosen a good mate.
When Zagreus brings up Ares' closeness to Nyx and questions whether Ares might have ulterior motives, Thanatos assures him not to worry, noting that the Olympians fear her.
Thanatos is quite perplexed when Zagreus tells him how much Ares sings his praises. When asked what his opinion is of Ares, Thanatos admits that he doesn't like Ares' views on death, but at least appreciates that he is genuinely cordial to him—unlike most other Olympians. Thanatos says he is fine, although Zagreus remarks that he's "disturbingly fine."
Hermes[]
Hermes: Fellow psychopomp.
Hermes is the only Olympian who frequently interacts with Thanatos. He mentions that they don’t usually run on the same track, though their paths occasionally cross. He finds Thanatos a strange guy, but apparently good at what he does.
Although Thanatos ends up encountering Hermes at some point and likes to stay well-informed at work, he finds Hermes’s way of delivering information irritating. He doesn’t like listening to him talk.
When Hermes meets him again, he says he saw Thanatos smile just from hearing Zagreus’s name — something he had never seen from him before.