* AluminumChristmasTrees: Chicken and waffles was not made up by Riordan. Sadie [[AudienceSurrogate mirrored a lot of readers]]' thoughts, since this was one way (the other being the [[https://www.potatopro.com/news/2016/lays-favorite-potato-chips-flavors-return-us-store-shelves-limited-time Lays 2013 contest winner]]) people found out this was a thing.
* BigLippedAlligatorMoment: In-universe, unintendedly exploited as ConfusionFu.
--> '''Ra''': Weasel Cookies!
--> '''Apophis''': [[FlatWhat (is diverted for a second)]]
* BrokenBase: Sadie and Anubis's relationship is either seen as ok or pedophilic at worst. Her love triangle between Walt and Anubis is also a point of contention.
* CompleteMonster: [[EvilSorcerer Setne]], from ''[[Literature/TheKaneChronicles The Serpent's Shadow]]'' and ''Literature/DemigodsAndMagicians'', son of Pharaoh [[UsefulNotes/RamsesII Ramses the Great]], was a murderer and blasphemer who escaped oblivion to return to Earth and sow chaos, being responsible for massive amounts of destruction, including UsefulNotes/TheFrenchRevolution and UsefulNotes/WorldWarI. While initially assisting the Kane siblings against Apophis, Setne betrays them to instead try to seize control of the great serpent, intending on feeding it many souls in the afterlife, his father included, before unleashing Apophis to destroy most of the world whereupon he will proceed to rule the rest. Upon failing in this, Setne later returns to attempt to [[GodEating devour the gods]] of every pantheon to make himself the supreme one god who will dominate the world entire.
* EvilIsCool: Set is a JerkassGod but he's also incredibly funny, suave and stylish as well. His chaos-based powers and charismatic approach make him quite the interesting villain to read about.
* FridgeBrilliance:
** In ''The Red Pyramid'', Thoth only agrees to help Carter and Sadie if they can prove that they're not going to just repeat the old stories over and over. Except for the times where they deliberately invoke the myths, such as repeating Ra's journey through the Duat, the Kane siblings don't repeat those stories as much as [[Literature/PercyJacksonAndTheOlympians the Greeks]], [[Literature/TheHeroesOfOlympus the Romans]], [[Literature/MagnusChaseAndTheGodsOfAsgard or the Aesir and Vanir]].
** Similarly, in the first book, Thoth explains to the Kane siblings (and the readers, by extension) that his name is [[YouCannotGraspTheTrueForm incomprehensible to spell out in English]], so he pronounces it "Jeh-hooty". So why do the other Egyptian deities use the Greek pronunciations (egregiously Anubis)? Easy - that's how they comprehend it, and, being [[UnreliableNarrator unreliable]], Carter and Sadie translated them to their more familiar Greek forms for you so you'd know who they're referencing. Not a lot of people would connect "Anapa" with "Anubis", for example.
** While likely unintentional, Anubis shifting in between his human and jackal selves while being with Sadie is a nod to his infamous reputation with furries in the modern day.
* FridgeHorror:
** Apophis awakening in Cairo probably killed thousands of people, given that he's a {{Kaiju}} and entered the city during the FinalBattle.
** Given he's the embodiment of chaos and destruction, and they specifically mention it's happening during the recent Egyptian revolution, this is true whether he personally crushed them or not.
** Walt hosting Anubis means that Walt will survive the family curse...but if he and Sadie have a child there's no chance that ''they'' will survive...
* FriendlyFandoms: Fans of trilogy became fans of ''Series/MoonKnight2022'' due to the use of Egyptian gods and the fact that both stories have Taweret appear as a friendly hippo with ''Kane Chronicles'' having her run a retirement home and ''Moon Knight'' has her in a mental asylum world. There's also a TwoPersonLoveTriangle between Layla, Marc and Steven just like Sadi, Walt and Anubis.
* GrowingTheBeard: While some agree that Riordan did this sometime during [[Literature/TheHeroesOfOlympus Heroes of Olympus]], some also think he did it somewhere during this book, usually "Serpent's Shadow".
* HilariousInHindsight: In ''Throne of Fire'', Set refuses to kill a monster for Carter and Sadie even after he promised to help, on the grounds that if he did, GETM (Gods for the Ethical Treatment of Monsters) would have his hide. Come ''Literature/TheTrialsOfApollo'', it turns out that the Greek gods at least banned the slaying of endangered monsters.
* MagnificentBastard: [[CardCarryingVillain Set]] is the GodOfEvil, who upon being freed from his imprisonment immediately traps Osiris in a coffin. Possessing Amos, Set has him sabotage Brooklyn House's security so he can send his minions after Horus and Isis' hosts, Carter and Sadie Kane. Having Amos save the siblings from Sobek, Set lures them to his pyramid so he can use them to power his storm which will engulf the world. Later summoned and [[SealedEvilInACan trapped in a jar]] by Vladimir Menshikov, Set exposes the invisible Carter so he and Sadie will be [[EnemyMine forced to free him]] to fight the more powerful Vladimir. Set gives Sadie the location of the last scroll of the Book of Ra in exchange for her ability to use his Ren, and departs in peace. To prepare for the battle against Apophis, Set teaches Amos his branch of divine magic and complies with his restraint when fighting the serpent's minions. Genuinely loyal to Ra, Set nevertheless stands by Horus' side when he ascends to King of the Gods, [[AndTheAdventureContinues seemingly with another plot already gleefully in mind]].
* OneTrueThreesome: Oddly enough for a kids book. In the end Sadie, Walt, and Anubis come to an arrangement, simplified because the later two now share a body.
* TearJerker:
** The first book has Bast's death. By the book's end, they fail to rescue their dad, they've lost practically everything and Carter's love interest was a ''statue''. Thankfully, their dad knew he wouldn't live but would be with his wife, they still have Amos and Bast (who got better), and Carter's love interest is thus still alive but sleeping, so BitterSweetEnding.
** And then Bes sacrificing his ''ren''-and with it, ''his mind''-so that the siblings have enough time to beat the BigBad of the second book.