|“||I try to do something nice, and this is my thanks? You should have let me kill them, Amos!||”|
–Set, in The Serpent's Shadow.
Set is the Egyptian god of deserts, storms, strength, chaos, and evil. He is the son of Geb and Nut, as well as the brother of Horus, Isis, Osiris, and Nephthys. Later, Horus would become his nephew and Nephthys would become his wife. He is the main antagonist of The Red Pyramid, but a minor supporting protagonist in the rest of the series.
Set, also called Seth, was born on the third Demon Day (December 29) to Geb and Nut as their third child. In time, Set would become the most powerful servant of Ra and was chiefly responsible for protecting him from Apophis. When Ra withdrew, Set was entrusted with protecting a third of the Book of Ra, which would awaken him. After his rebirth, Set married his former sister, Nephthys and fathered an estranged son named Anubis with her. When Osiris became king of the gods, Set refused to stand for it and planned to kill him. During the king's birthday celebration, he trapped Osiris inside a magnificent sarcophagus and poured molten lead into it. Declaring himself ruler, he relentlessly hounded a pregnant Isis who would give birth to a reborn Horus and resurrect Osiris. Although Osiris could not be truly revived, Horus would go on to avenge his father's murder by dethroning Set.
Set was originally a major god of Upper Egypt. He was viewed as a benevolent god and protector, though he has a long history of feuding with Horus. When Upper and Lower Egypt merged, the followers of Horus gained power and increasingly demonized Set. He went from being a chief god to Ra's protector, to being merged with Apophis. Despite this, he was still in some areas a major god and has had several revivals.
Set, along with his brothers and sisters, is released by Julius Kane while attempting to summon Osiris. He kidnaps Julius who has become the host for Osiris and possesses Amos Kane. He then commands the demons under his command to construct a pyramid in Phoenix, Arizona to serve as both a medium for his power and a vessel for his being. He originally intends to turn all of North America into a desert but is manipulated by Apophis into targeting the entire world by possessing his lieutenant Face of Horror. Set also tries to capture and destroy the Kanes by possessing their uncle Amos Kane who he releases once he lures the Kanes to the Red Pyramid. He tries to steal the power of Nephthys from Zia Rashid, but is shocked to discover Zia is not Nephthys' host, not knowing Zia is actually a shabti. Set battles the Kanes at the Red Pyramid after Carter merges completely with Horus. After Sadie learns Set's secret name Evil Day from Zia, she merges completely with Isis to face Set. When he points out they are in the source of his power, the desert and that a magician can't open a portal during the Demon Days, Sadie reveals her merging with Isis and transports Set, the pyramid, his army and the magicians battling them as well as herself and Carter to Washington, DC, weakening Set. There, Carter holds him off while Sadie casts the banishing spell from the Book of Overcoming Set, but realizes that Apophis is the true enemy and stops the spell just in time before the banishment is complete, using the Feather of Truth to show Apophis in the sky instead, revealing that he'd been using Set to create enough Chaos that he could escape his prison. Carter kills Face of Horror and they show Set how he was manipulated and offer him a deal: if he leaves and doesn't come back until they summon him to help fight Apophis, they will let him go. Set agrees to the deal and swears on his secret name and Ra's throne and departs as ordered by Sadie.
Set reappears when Vladimir Menshikov summons him inside of a malachite jar. As Menshikov knows his secret name, he is forced to reveal the properties of Apophis' prison, Set notices the Kane children saying he needs a sacrifice "and a magician who can't do a proper invisibility spell-like Carter Kane over there" would be perfect, alerting Menshikov to their presence with the intention of gaining freedom. When Vladimir is about to attack them, Sadie destroys the jar and frees Set who incapacitates the rogue magician and allows the siblings to escape as thanks.
After the Tjesu heru poisons Carter, he helps Sadie get her brother back to safety with Bes and also gives her the location of the last part of The Book of Ra in exchange for his secret name. At first, Sadie didn't agree because she thought he was about to kill her, but after she gives back his secret name, he doesn't kill her and says "I hope you live, after all, Sadie Kane. You're quite amusing. But if they do kill you, at least enjoy the experience!" Bes confirms that Set would know as Ra's priests had given it to him to hide. Sadie agrees to this but makes the god swear to a truce with her family before the exchange. He also reveals the location of Zia Rashid to Sadie, though Sadie remains suspicious of his motives as he is a god of evil and Apophis told Carter where to look too, though not as well as Set. Set departs to Sadie's surprise without trying to harm them, keeping his word. Set is later seen when Ra retakes the divine throne.
Needing more power, Amos Kane begins following the Path of Set, learning how to channel the god's power. This leaves Zia, Sadie and Carter worried about him as they worry that Set may be manipulating Amos again. Set later appears to Carter on the Egyptian Queen and assures Carter that he is not manipulating Amos and indicates that Amos was the one who in fact sent him. Set indicates that he simply exists as a balance to the other gods who are good as he is a god of evil and that he is a necessary evil. However, Set reminds Carter that he used to be Ra's lieutenant and assures him that the last thing he wants is Apophis to win, saying that between Ra and Apophis, he'd take Ra every time. Later, Amos hosts Set again, but this time Amos is in control, though he seems to struggle sometimes with Set's more violent tenancies. Carter uses this as proof to the rebels that they are not evil. Set, hosted by Amos, participates in the battle against Apophis and leaves Earth with the other gods when Sadie and Carter destroy the Serpent. He is later seen in the throne room of the gods when Horus is made pharaoh again, supporting him but with a smile that suggests he has something evil planned.
Set is arrogant, cunning, cruel, manipulative, and enjoys toying with his enemies often for his own personal entertainment. As the god of evil, Sadie described Set as being ruthless, and cruel, to which he sarcastically replies, "You make me blush, Sister." Set's first concern is always himself and he even is willing to submit to his enemies if it is in his best interest, like he initially did with Menshikov. Ironically, while he was able to manipulate Amos by partially possessing him, Set himself was being manipulated by Apophis, his former mortal enemy, through Face of Horror. When Set finally realizes this at the end of The Red Pyramid, and the threat that the Serpent poses, he stops trying to create Chaos, works with the Kanes to stop Apophis, and later even allows Amos Kane to channel his power in battle so that he could fight the Serpent. Despite being cruel and manipulative, his father Geb claims that Set is "more than he appears", as he is of Geb's own flesh and blood. In The Serpent's Shadow, Set explains that while he is the god of evil, he simply exists as a balance of necessary evil for all of the gods who are good. Thus, unlike the purely evil Apophis, Set does have a more honorable side to him, being fiercely loyal to his master Ra. Due to this, Set admits to Carter that the last thing he wants is Apophis to win and that between Ra and Apophis, he'd side with Ra every time, even though he's a Chaos god too. So, ultimately, Set chose to confront the Chaos Serpent along with Ra. Throughout the books, Set has also shown to have a dark and sarcastic sense of humor.
Set has multiple forms due to shape-shifting capabilities, and has appeared in several ways, but always contains some form of the color red, throughout the series.
The first form he was seen in was that of the fiery outline of a man; a head of a Set animal sometimes appears on this form or an almost human face with pale skin, cruel, angular features, and glowing red eyes. Throughout The Red Pyramid, he appeared as a tall and strong, almost a twin to Osiris, but with dark red skin, a handsome, but cruel face, a pointed black beard, and red eyes. His face sometimes flickers between that of a human and the Set animal. When he smiles, his teeth turn into fangs. Later, in The Serpent's Shadow, he takes on the form of Amos while meeting Carter on "The Egyptian Queen."
He sometimes wears blood-colored robes, red combat fatigues, fiery-red armor, or a red silk suit. Set's blood is black, as shown when Carter stabs him during their battle.
His true form in the Duat, however is, as Sadie describes it, a mountain of sand, doused with petrol, set on fire, spinning in the world's largest blender.
Even though his laugh usually sounds cruel, screeching, and gleeful (which "cut through Carter like a chainsaw"), when Set arrives at Osiris's birthday, his laugh is described as "wonderful" by Sadie.
- Massive Strength: Set has incredible strength, even for a god. He once simply stamped the floor and it shook from the force, and made all of the other gods present "topple over each other like dominoes". As Ra's lieutenant, he was strong enough to help Ra fight against Apophis.
- Superhuman Reflexes: Set has superhumanly quick reflexes, as he was able to instantly deflect Isis' lightning bolt and later, Zia's fire blasts in The Red Pyramid.
- Mental Fortitude: Set was completely unfazed by Bes' Boo in The Throne of Fire.
- Combat Magic: He has his own combat avatar which unlike other which are made of colored energy, his is made of sand and fire. His staff when used is mimicked by a ten-meter sand/fire staff. Storm magic can be used with this avatar.
- Fire Magic (limited): Set can also control fire to an extent.
- Storm Magic: As the god of the desert, he often attacks enemies with blasts of sand from his staff and when he is in his source of power, the desert, he can create huge storms to the point he once created the Sahara desert. He is at his strongest in his domain, and not even Horus and Isis can defeat him there. With the additional energy from the Red Pyramid at full power with all his siblings entombed, he can grow in size larger than a Horus avatar, and can create a storm large enough to swallow all of North America, and Amos believed if he unleashed a large blast of storm magic the resulting chaos would give Set a near invincible form. He can also summon bolts of red lightning, also from his staff.
- Telekinesis: Set is quite skilled in telekinesis, shown when he forcibly levitated Isis in the air and sealed her mouth shut. Later in The Red Pyramid, Set was able to telekinetically pin Carter against a wall, and summon Zia towards him simultaneously, without breaking concentration.
- Demon Wings: Set can instantly sprout dark demonic wings and fly when he needs to.
- Infertility: When he was fighting Horus, he lost a testicle, that is why the deserts where always infertile.
- Desert/Chaos Empowerment: It has been shown that he is much stronger in his domain, the desert, to point that, with the Red Pyramid almost completed, he was able to overpower both Isis and Horus. Also, Amos theorized that if Set created a big enough storm, the resulting chaos would give him an almost invincible form.
Nephthys: Despite their marriage, the two do not seem to trust one another. Although she does love him, Nephthys knows that Set is dangerous and aids in the battle against him. However, it is hinted that Set also loves her, as when she betrays Set to let Isis escape, he doesn't harm her. Also Set has told Nephthys his Secret Name showing some evidence of love. She also gave away their only son, Anubis, claiming that she did not want him to meet his father.
Osiris: Set seems to hold a hatred for Osiris, possibly because Osiris replaced Ra as the king of the gods. Set has made many spiteful actions against Osiris and seems to actively attempt to cause him suffering.
Ra: Set was said to have been Ra's lieutenant, indicating that he was fiercely loyal to him (in fact some myth states that he was the only god that helped Ra through the centuries against Apophis). This loyalty would add to Set's hatred for Osiris. Set confirms his loyalty to Ra to Carter saying that he prefers Ra to Apophis who is a god of evil like Set and refers to himself as the "loyal opposition."
Anubis: Anubis, despite being Set's son, has never actually met him before The Serpent's Shadow. He is reluctant to admit to Sadie that Set is his father, but helps defeating him by giving them the Feather of Truth to save Osiris, the only family he ever had. The two apparently meet for the first time when they battle the rebels together and Set is impressed when Anubis kills Sarah Jacobi, complimenting him on his actions. However, Anubis shows dislike towards him and his praise telling him "shut up, Father".
Carter and Sadie Kane: Set was Carter and Sadie's first enemy and throughout The Red Pyramid battled them until they defeated him and forced him to side with them using his secret name. They also make him realize that he is being used. Despite their status as his enemies, after The Red Pyramid, Set never actively tries to hurt them and helps them a few times. He exposes the invisible Carter to Vladimir Menshikov in an attempt to escape and in thanks for being released, he holds Menshikov off so they can escape. Set then helps Sadie carry the fatally poisoned Carter to Bes and tells them where to find the last part of the Book of Ra in exchange for his secret name back, but gives them the location of Zia Rashid without anything in it for himself. He keeps to the truce they set up even after its officially over through The Throne of Fire and The Serpent's Shadow and even appears to Carter to reassure him that he isn't controlling his uncle like he fears and warns him of an upcoming attack though he doesn't help with it.
Amos Kane: When Set is first set free, he possesses Amos and uses him as one of his hosts throughout The Red Pyramid, using him to go after Carter and Sadie. Set nearly burns out Amos' soul from the possession and abandons him, leaving him in a depressed and weakened state for a long time. However, Amos apparently gains an understanding of Set from the incident and when he decides to follow the Path of the Gods, he chooses to follow the Path of Set, drawing on Set for power and apparently communicating with him. Set works with Amos against Apophis, willingly sharing his power and it's indicated visiting Carter to ease his worries at Amos' request. During the final battle, Set takes Amos as a host again, but this time with Amos in control with Set seeming to mostly let him except when he tries to have "fun" by killing people, but Amos is able to keep him under control, something that is supposed to be impossible.
- Set has the specialty of fire, combat, and dark magic.
- Set says he wishes his secret name (Evil Day) was something else, such as "Rockin' Red Reaper" or "Glorious Day".
- In The Red Pyramid, Set was first considered to be the main villain, but he later helps fight against Apophis, the actual villain. This makes him similar to Hades in The Lightning Thief, who later helped fight against Kronos. Set's role, however, is initially more sinister in the first book than Hades's.
- Set's blood is black, as shown when Carter stabs him.
- Set enjoys eating white chocolate pawns, as seen in The Throne of Fire.
- His Norse counterpart is Loki .