Thanatos

Thanatos is the personification of death. He is one of Nyx's many children and the twin brother of Hypnos.

As the embodiment of death, Thanatos has many duties requiring him to venture up into the mortal realm. His most recent such venture took longer than usual - speculated by Hypnos and Zagreus to be related to the ongoing war - but returns some time after the game's opening. He apparently dislikes the mortal realm, in particular how bright it can get.

Thanatos occasionally appears at the beginning of regular encounters and challenges Zagreus to see which of them can slay more shades. He is immune to damage during the contest, and will not retaliate if struck (he'll just complain). If Zagreus either kills more enemies than Thanatos does or ties his total, he will award Zagreus a Centaur Heart in addition to the regular room-clear reward.

Within the House of Hades, Thanatos can be found in the same hallway where Achilles keeps guard. After a run in which he was encountered, he has a high (but not 100%) chance of appearing in the House. If he is given nectar during the run right before appearing in the House, he won't be able to be gifted.

Affinity
If given Nectar, Thanatos will give you the Pierced Butterfly.

After 6 bottles of Nectar, further gifts will be locked until you complete his favor.

After completing his favor, giving Thanatos Ambrosia will give you Companion Mort in exchange.

Thanatos' affinity gauge is maxed out at 10 hearts, requiring the gifting of 6 Nectar and 4 Ambrosia total.

Favor
Thanatos' favor is not mentioned, and acts more as a narrative event between Zagreus and Thanatos.

Beating Thanatos after giving him 6 Nectar will randomly prompt a discussion between the two about Zagreus being powerful enough to escape the Underworld without Thanatos' help. Once Zagreus proves his strength to Thanatos, Thanatos can be given Ambrosia the next time he is encountered in the House of Hades.

Romance
Reaching maximum affinity with Thanatos will unlock a scene in Zagreus's Room, where Zagreus can either begin a romantic relationship with him or continue as friends. Thanatos, Dusa, and Megaera can be romanced at the same time with no negative repercussions.

If Zagreus is able to fully romance both Thanatos and Megaera, another scene will be unlocked in Zagreus’s Room, in which he, Thanatos and Megaera meet up and can begin a polyamorous relationship.

Quotes
"For quotes and dialogue regarding, please refer to /Quotes."

Encounters
After seeing either Alecto or Tisiphone for the first time, Thanatos has a chance to first be seen after the 3rd chamber of Elysium. After this, Thanatos has a chance to appear in any area except for the Temple of Styx. He may appear at the beginning of any encounter (excluding Trials of the Gods or Survival Rooms). This initiates a contest where they compete to slay more foes than the other, for that encounter. The spawn rate of foes is noticeably higher and the encounter lasts three waves. If Zagreus either kills more enemies than Thanatos does or ties his total, he will award Zagreus a Centaur Heart. Zagreus and Thanatos are immune from each other's attacks.

Thanatos has two types of attacks that can instantly kill foes, even those with armor, during the contest:


 * He spawns a large purple circle which, after a delay, instantly kills foes inside the area of effect.
 * He marks an enemy with a purple scythe on their head, which kills it after a delay.

Thanatos's attacks are slow and delayed, which gives Zagreus a chance to kill the enemies and claim more points.

In Elysium, Flame Wheels that self-destruct are not counted as points. Exalted warriors count as two points, once when they are wielding weapons, and another time when they are in their weapon-less soul form. Exalted warriors will not spawn a soul when Thanatos kills them, but only count as one point for him.

Relationships
Nyx: Thanatos greatly respects his mother and constantly shows deference to her. He knows her well enough to know she rarely changes her mind on matters regarding the state of the House of Hades. As his mother and superior, Nyx encourages Thanatos to put his best effort in his work, due to its importance.

Hypnos: Thanatos initially appears rather cold towards his brother, largely ignoring him for long periods while occupied with his work. However, he does care for Hypnos, and intervenes when Hypnos is at risk of losing his job as the attendant to the House of Hades. It is through his and Zagreus' encouragement that Hypnos starts improving in his work, through discovering and embracing Hypnos' love of creating lists to help him plan out his time better. Zagreus also encourages Thanatos to be more outwardly kind to Hypnos, and their relationship improves from there.

Charon: Charon is enigmatic to the many denizens of the Underworld, Thanatos included. Even when asked by Zagreus, Thanatos is unable to reveal any information about Charon or his plans, suggesting that Zagreus might know the boatman better than he does.

Eris and Nemesis: Thanatos is not close to his sisters, but acknowledges their roles in providing shades for the Underworld. He seldom brings them up, and is hesitant to even evoke their names.

The Fates: Despite all being children of Nyx, Thanatos isn't close or even in contact with his prophetic sisters.

Zagreus: Zagreus and Thanatos are childhood friends, and share a strong bond, despite having opposite personalities. This is possibly because of his status as a god of death, and Zagreus' role of a god of life, blood, and rebirth. Thanatos was initially visibly hurt when Zagreus decided to leave the Underworld, as he had neglected to inform the god of death. However, he continues to assist the son of Hades at times. The two may form a romantic relationship, should Zagreus choose to pursue one.

Megaera: Megaera and Thanatos are work colleagues and friends, having bonded over their mutual frustration over being tricked by Sisyphus in the past.

Sisyphus: The former king had once tricked Thanatos to dodge his own death. This earned the ire of the god of Death, as well as many of the other gods of the Underworld. His ire continues to persist, even ages after the fact, and continues to distrust Sisyphus despite his changed demeanor after being punished, and even with Zagreus' support of the former king.

Additional notes

 * Thanatos has no requirements which must be unlocked before he returns to the Underworld.
 * While his relationship with Zagreus is officially described as childhood friends, Thanatos will make several remarks about having met Persephone through the course of the game, while Zagreus never knew previously that she was his mother. Some confusion about this may arise from the Portrait, Cerberus item that can be purchased at the Contractor, but this item does not depict canon events due to Skelly's inclusion in the image.