* Why are children of the same god exactly the same?
** A lot of readers (especially fanfiction writers) think demigods in the same cabin, will have identical personalities and skill. There will be inherent similarities yes, but still they're still individuals, as Piper and Frank proved. Especially for gods who are patrons of a bunch of stuff. (Eg. Apollo - music, medicine, light, the sun, truth, prophecy, healing, plague, poetry and art. Athena - wisdom, war, crafts, strategy, inspiration, civilization, law/justice, mathematics and skill). That's a broad range. Athena's kids can range from hard-out warriors to philosophers. They don't necessarily inherit all those aspects, just a few. Why do people think demigods are expy's of thier parents/established characters?

* Why have the giants in the first two books come across as so weak? They were supposed to be the greatest threat to Olympus. Yet they have all been dispatched fairly easily especially Polybotes and Alcyoneus who were made to counter two of the strongest gods. With Porphyrion at least there is an excuse of being still weak. The other giants are just big and hard to kill. They lack the other powers that make the gods and Titans so dangerous. At this rate all you need to do is arm the demigods with parts of Terminus' statues to win. Who needs the gods to defeat them when Percy can with ease defeat the one meant to counter his father?
** Much like Kronos, the giants aren't at full power yet, they've only just resurrected. If/when they reach full strength, they'd rip through a demigod like tissue paper.

* Ok, so in Roman Mythology, Saturn (aka Kronos) was actually a great guy. It's actually kind of funny. In The Last Olympian, when Hades fights him in front of Olympus, we hear Demeter say that Kronos has no appreciation of agriculture. Well, guess what! In ROMAN mythology Kronos (Saturn) is the God of the harvest and agriculture! More than that, in Roman mythos, when Saturn was defeated by Jupiter, apparently he was never imprisoned, and he fled to Rome and ushered in a golden age of Prosperity. So, 1, why do they (the Roman demigod faction) still honor the Olympians if Saturn is so good to them, and 2) why did they even try to (unknowingly) help in the war with Kronos by destroying Mt Othrys?
** First, the Olympians are their parents and all demigods seem to feel some degree of loyalty due to that. The Olympians were also the ones who helped make Rome into a great empire and sustained it. Third, the Olympians are the ones in power and can make your life very miserable if you do not do what they say. As for Saturn, he was thought of as radically different from Kronos, moreso than even Mars and Ares. Saturn was a benevolent god of agriculture while Kronos is an evil god of devouring time. Maybe Saturn is actually a different god if Kronos was imprisoned so long ago. The Greeks equated the Olympians with Egyptian gods, but the two are completely separate pantheons.
** Besides, that was Saturn, not all the Titans. And maybe his personality changed- there's no point in honouring someone when they're trying to kill you.
** Or maybe that's why there were demigods that Percy didn't recognize at first, because they were Romans
** its possible that the Romans were actually fighting the Greek version but thought it was the Roman one, also even though Saturn was consider a good person, the Roman Demigods are willing to fight anything as long as the gods say so, and obviously have a more stronger loyalty to the gods than the greek(in Mars entry into the camp, the entire camp,except Percy, bow down, in Greek Camp the demigods talk back to gods(especially Dionysus) without a second thought).
*** Or maybe, the Romans weren't fighting Kronos . . . remember how Kronos was attacking the Eastern seaboard? Krios was the Titan of the southern lands, if memory is serving me correctly. Although Camp Jupiter may've named their elephant Hannibal, they were not big fans of the original.

* Riordan says that the gods and all thing mythography can be found at the centre of Western Civilization. So at the time of the American Civil War would the Gods not be in the UK, seeing as it was TheEmpire of the time? Or at least somewhere in Europe?
** The gods didn't necessarily have to be in America for there to be demigods there. Maybe they were based in Europe at the time but some of their children were living over there.
** Well I'd expect Camp Half Blood to be near Olympus, as it is now. I would make no sense for the Camp to be in America while the gods are in Europe
** Pretty sure Camp Half-Blood was only started up after WWII anyway, so as long as there were some Greek demigods in the country, their involvement in the Civil War could be as stated. The real question is what were the ''Romans'' doing in America then? They have much more structure, and would probably stick close to Olympus even more than the Greeks (being much better organized...)
*** Didn't Hazel mention that the Legion follows Rome, not Olympus? Sure it could have been in the British Empire for a time, but isn't it also true that America was founded in the spirit of the Roman Republic?
*** Unless Camp Half Blood was in the UK and was literally picked up and moved to America, I think we have to assume that it was there in America during the American Civil War given Bunker 9. As for why it is there, well America was a new land, so maybe the God's thought it would be safer for them to train there.
*** When you consider that the Gods moved with 'the heart of Western Civilization' it's not difficult to see that once the ideals held by that concept became more pronounced in America, the Gods simply moved there. I'm guessing it happened sometime between the Revolution and the Civil War.
* Why, oh why, did Piper have to give her father that drink? Surely the Mist could have taken care of it? Especially since it's explicitly stated that it's the knowledge that these things are real that is breaking him. I could be appeased on this one, but either Tristan like Rachel and Percy's mom can see through the Mist, or Gaea can control the Mist (which would be considerably ''nastier'').
** I always assumed there was a point where even mortals could see the Mist after a while- it was just something that blocked them in passing, and their imagination did most of the work, and that open-minded people could see through it. So if they were or confronted with something for a long time, then even a human wouldn't be able to lie to themselves anymore- Like... magical denial; it can only do so much. But now that you mention it, this really was just an assumption on my part. I'd call it Gaia's manipulation of the Mist, since it's stated to be possible for gods, whereas her father's potential ability was never mentioned.
** I don't recall anyone of them being able to manipulate the Mist. Besides, he was kidnapped by a giant and held prisoner by Earthborn, it'd be a bit difficult to convince him that he didn't see anything.
** Thalia could manipulate the Mist, as could Chiron.

* It bugs me that they just spent five books looking for half-blood children of the Big Three, and no-one thought to mention that there's a Son of Zeus claimed twelve years ago only a few months younger than Percy. I know Chiron didn't know what was happening at the other camp, and the gods were keeping it quiet, but you'd think Kronos would have mentioned it. And that Hades wouldn't think Nico was next in line.
** Hades might not have known. If he has no Roman children at the moment, he might not have had a reason to keep an eye on the Roman camp. Or, maybe Jason's effectively being adopted by Hera/Juno put him out of the running.
*** Or maybe the prophecy only applied to the Greek side of things.
**** When the group faced Enceladus, he mentioned how Jason defeated the Titan Krios, and toppled the Black Throne, so there was probably separate prophecies for both camps, so yeah, only Greek children applied for the Greek prophecy, and Romans for the Roman.
***** That doesn't make sense because the Seven Halfbloods prophecy applies to both of them. The line explicitly called it a "halfblood child of the ''eldest gods''". Maybe they just assumed it would only apply to their eldest form, the Greek version.
****** Probably because the Prophecy of the Seven is forcing them to work together, none of the other prophecies even Great Prophecies had to
**** It does. Remember how Neptune isn't important in Rome? And no one likes Pluto kids (Well, this is actually true at the Greek camp as well, but still)? The camp's most important people are Jupiter and Mars. There's not really a big three. And it also said that the prophecy of seven has been around for centuries, implying that it has been the Roman's "Great Prophecy." There are also a ton more minor Roman gods.
** Besides, he's not a son of Zeus, he's a son of Jupiter. The prophecy probably did only apply to the Greeks, because otherwise, how would they have got to Jason? At this point, nobody except Chiron and Lupa knew about the other camps, and they probably talked and realised that there were two different prophecies and thus no interaction was needed.

* Why didn't Grover use his empathy link to figure out where Percy is?
** Given how often the link got used in the previous series, it's likely the gods know about it and Hera took steps to block it somehow so Grover couldn't do just that. He probably tried, but seeing as he's completely OutOfFocus, we don't know for sure. Or it may have just been a side effect of Percy having his memories stolen. Empathy bonds aren't perfect. Remember how they couldn't find Grover for like two months prior to ''The Last Olympian''?
** Close enough, Hera didn't need Percy yet, she took hm out of commission for 8 months possibly in magical sleep, the same thing that prevented Percy from finding grover, since Morpheus put him out.
** its pretty much stated by the Faun guy Don during the feast of Fortuna that his empathy link was "supressed" so Hera probably took steps to take it out.

* The climax of ''The Lost Hero'' is full of continuity errors. Hera, once freed, goes nuclear, destroys all the enemies and sends the Big Bad running. If gods can do that, why didn't Artemis do it once she was set free in ''The Titan's Curse'' instead of being nearly killed by Atlas and losing her trusted lieutenant? The previous series also made it quite clear that anyone who looked at a god in their true form would be incinerated into a pile of ashes, but Jason sees Hera's true form and is merely driven into some sort of coma that Piper can bring him out of with her voice.
** That's most likely ContinuityDrift at work. Riordan's done it before. Remember how Annabeth had only heard parts of the Great Prophecy in the first book but then she said she'd known the whole thing in TLO?
** In TLO it's reveal that the prophecy was actually a piece of paper in the beads of the mummy's necklace, Annabeth probably search in the attics between Quests till she found it.
*** Atlas was a Titan at full strength. Porphyrion was still groggy, and it was explicitly stated no less than three times that a demigod and a god attacking a Giant together could kill them. Any non-moron would run.
**** True, anybody with an ounce of sense would have run, and Riordan/Jason lampshades this when Porphyrion is taken aback by the sheer stupidity of it. In Jason's defense, though, he wasn't trying to beat the giant all by himself. He was just trying to buy Leo and Piper enough time to free Hera, and after that Hera could help them bring Porphyrion down.
** The Jason-survives-seeing-Hera's-true-form thing is a plot hole that is almost certain to be addressed later in the series.
*** It's also possible that some of the potency was lost because Hera was in her Greek form and Jason is Roman. (WMG)
*** I just saw it as Piper's Charmspeaking being so powerful that her voice was able to bring Jason back to life before he was too far gone, so whether it's a plot hole or not is up in the air.
*** I doubt casting CharmPerson would bring someone ''back to life'', considering its only real power is in manipulating people to do things they already could. Even when she commands the {{Mooks}} to sleep, they were technically able to do so. But Jason clearly wasn't dying because he wasn't motivated enough.
*** Riordan [[WordOfGod writes the rules]]. If charmspeak can prevent death, [[MagicAIsMagicA then charmspeak can prevent death]]. Also, given the [[PowerOfLove goddess it belongs to]], it's likely [[BackFromTheDead that aspect]] of charmspeak only works on loved ones.
*** Earlier in the book, Jason saw Hera's true form in a dream. Maybe he could survive because he had already been exposed to it. Kind of like a vaccination.
*** Perhaps justified by ''The Son of Neptune.'' [[spoiler: DeathIsCheap now applies to everyone, because Thanatos, the god of Death, has been imprisoned. It's very possible for Jason to simply have come back to life if Thanatos had been imprisoned by then.]] Though it still doesn't explain why Jason wasn't burned to ashes...
*** As far as 'burned to ashes', it's quite likely there was divine intervention from Zeus/Juptier. How else would Jason still be alive after seeing Hera's true form, otherwise his soul couldn't come back, even with the Doors of Death open. It's still possible that Charmspeak could bring back the dead (it's entire power is suggestion, and if there's one thing that's clear in this series, dead things are much easier to call than you'd think), but we'll see. That's probably the point here: any one of these could have happened, but it's far more likely more than one happened at once. Hera's "Impossible!" response to Jason being alive at all afterward is quite telling.
** Because what if Artemis had killed someone else? Like Percy, or Thalia, or Zoe, or Annabeth? And it might not have been on her mind at that moment.
*** Perhaps Artemis was already severely weakened from holding up the sky, and Hera was just more or less caged?

* Jason is fluent in Latin rather than Greek. But from what we know, Latin was primarily a written language; the Romans spoke Greek. So it's still of course possible for someone to speak Latin, but speaking-wise, Greek should come more naturally to Jason as a spoken language than Latin.
** Latin was most definitely the liturgical language of ancient Rome so it makes sense that the children of ''gods'' would speak the ''religious'' language. Also, only the Roman upper elite spoke Greek, mostly due to snobbery and CulturalCringe (rather like how, in 18th and 19th century Europe, everyone was obsessed with speaking French for some reason). The common language of the people was [[http://en.wikipedia.org/wiki/Vulgar_Latin Vulgar Latin]].

* At one point, Leo has a thought about someone dying and hoping they stay in the Fields of Punishment forever. But it's been shown dozens of times that Leo's grasp of Greek mythology is basically zero; how would he have known about the Fields of Punishment but not, say, who Hephaestus was?
** Well there are two possible explanations. The first is just that, he didn't know who Hephaestus but he knows about the Greek Underworld. It's how it works in the real world afterall, you might know something complicated about a subject, but not know something relatively easy about the same subject. The second is that in between scenes that we never saw (such as when Jason or Piper was asleep and the others were awake), the other one explained it to Leo.
** Another option is that Leo did in fact learn of the Greek Underworld in classes that taught it. Sure, at the time he probably didn't pay a whole lot of attention, because it would have been before his heritage was discovered, but once it was he could have just put it all in place.
* Since Zeus/Jupiter has come across as one of the biggest morons and jerks in both series do you think he'll be redeemed in the end? In the first book alone he made the same mistake he did against the Titans and was willing to risk the rise of Polypherion and sacrifice Hera just for a party. Jason gave a speech at the end about Zeus having to set an example and frustrated by the other gods challenging his decisions, but from what we've seen so far he does a poor job at the former and the latter is very much understandable. Even Thalia wants nothing to do with him. Do you think he is just a lot better as Jupiter instead of Zeus?
** Zeus's modus operandi in most of Greek mythology boiled down to [[ScrewTheRulesIMakeThem Screw The Rules, I Make Them!]], with the whole idea that he ''never'' learned. Given that the Roman aspects are implied to be more warlike and violent, "redeeming" him would mean heavy BroadStrokes, something Riordan has otherwise proven very good about averting.
*** True, but at the same time the Roman Mars is looked at in a much better light than the Greek Ares. Jupiter was also stated to be a more mature, formal, and stoic version of Zeus.
** Mars wasn't really shown in a better light per se. He was still his explosive, hot headed, self-righteous self. He was a bit tamed down, but not much.
** I think this question really goes to trying to figure out just how different the Roman Aspects are to their Greek Counterparts. The number of times we see Zeus are exclusively at Olympus during one of the 'God Meetings.' There, he's shown to be brash, quick to judge, and exceedingly arrogant, but not totally evil or harsh.

* What bugged ''me'' was mostly minor, but the descriptions of Walnut Creek and the bay area. for one thing, It ''does'' get cold in WC in the winter- it frosts, sleets, and you go out in a warm coat and gloves, not one layer or a tee shirt( like Jason). I don't recall the wording, but when they wake up at the cafe, there is a line like " winter wasn't even a concept.' or something. also, it does snow on mount Diablo they even have to close the mountain to tourists and hikers sometimes. And while the Bekeley hills ''do'' hold back the fog- they are only 'golden brown' in the summer time. All that fog- those hills are freaking ''green'' at Christmas time.Aand lastly- THERE ARE NO EUCALYPTUS TREES in Walnut Creek, and even if they were, they aren't as overpowering as the book says, unless there is a whole forest of them. I live next door to a grove of about 25 of them, and only smell them if i'm outside and right in the middle of them, and they've had broken branches.
** Riordan is from Texas. It is likely that he has no idea what California is really like other than what the stereotypes are and what he learns from different sources of media (AKA Hollywood)
** Generally speaking, Riordan's descriptions of places need to be taken with a grain of salt. In both series he's gotten details wrong about places (the Hoover Dam being the most glaring example...)

* Someone please clarify... if Leo is in fact Sammy's grandson, doesn't that imply Sammy in fact married someone else despite according to Gaea not getting over Hazel? And was the grandfather-grandson connection stated in either book or is it just fanon? And I really hope a love triangle doesn't erupt between Frank, Hazel, and Leo because that would NOT help matters between the two camps.
** I think it's fanon, but I'll probably have to check. Regardless, it's very possible to for Sammy to have started a family on his own. He may never have really gotten over Hazel, a giant what-if in the back of his mind, but he may have moved on just enough to find someone new. Perhaps she could never compare to Hazel, but she was good enough. And unless Leo is really Sammy reincarnated, I doubt a love triangle will start so easily; you are not the same as your grandparents, after all.
*** Sammy DID start a family after Hazel died. Any connection to Leo besides his looks, however, hasn't been mentioned. From page 424:
--->'''Gaea''': You were destined to marry Sammy. Do you know what happened to him after you died in Alaska? He grew up and moved to Texas. He married and had a family. But he never forgot you. He always wondered why you disappeared.
*** Hazel said Sammy's last name IS Valdez so this is probably a case of Identical Grandson, and I think it would be entertaining to have a love triangle with Hazel seeing how different Leo is from Sammy while reconciling her now current feelings for Frank
*** OP here: yeah, I reread and it did say Sammy got married... so oh dear Leo is probably Sammy's grandson. Octavian is going to love the two love triangles that will be happening in the third book.
*** Leo may not be Sammy's grandson. What if Sammy got Elysium and decided to be reborn to go to the Islands of Blest? (I'm not positive how this works, if you look the same or not)
**** Well, according to TheKaneChronicles (they're explicitly in the same universe), the afterlife is whatever you believe. So Egyptians get their souls weighed by Osiris while the Greeks go to the Underworld; in The Throne of Fire, it says that there are Romans that ended up in the Egyptian afterlife because they spent so much time in Egypt that they started to believe in the Egyptian afterlife. So Sammy would have had no reason to believe in the Greek afterlife, and probably wouldn't have been there at all.
***** Not quite that simple. In the first book a preacher died and went to Hades. It was commented that what he saw was the Christian afterlife and not the Greek one. Despite few people believing in it Hades has been receiving a constant stream of souls for thousands of years. Its why he stated the underworld is almost overflowing.
*** [[spoiler: As ''Mark of Athena'' states, Leo is Sammy's great-grandson, and definitely not his reincarnation. Simply a case of IdenticalGrandson.]]

* In ''Son of Neptune'', there's only the 12th Legion present at Camp Jupiter. So why did Jason claimed to be praetor of the 1st Legion in ''The Lost Hero''?
** I'm guessing that Riordan changed the legions between novels. That, or Jason mixed up the numbers.
** Riordan probably origionally was going to have multiple legions similar to Camp Half Blood's cabins (Cabin One=First Legion)but later changed this as it didn't really fit.

* Wait, so if it takes a god and a demigod to kill a giant, how did [[spoiler: Frank and Hazel take down Alcyoneus?]]
** I was wondering that too, maybe some unseen help from Thanatos?
*** Maybe Arion qualified? He is the immortal son of Poseidon and Demeter.
**** It was explicitly stated that Alcyoneus was different, that he was immortal only on his home ground. Once they took him out of Alaska, he was just as vulnerable as any monster.
**** And this is made more explicit in ''Mark of Athena'', where it's outright stated that Alcyoneus was the exception.
***** I always figured it was cuz Gaea was like, right there with em, and that she counted.

* In ''The Son of Neptune'', what happened to Nico? I really don't get why he wouldn't recognize Percy. Percy, of course, wouldn't know him due to his memory loss, but why doesn't Nico know Percy?
** He did, he was just pretending not to.
** Why?
*** If ''this'' isn't recognition, I don't know what is. Nico knows he can't interfere in Hera's plans, and that it's up to Percy to regain his lost memories. He knows that this is Percy's quest to finish.
--> For a microsecond when he saw Percy, the boy seemed shocked – panicked even, like he’d been caught in a searchlight.\\
Hazel hesitated. Something about her brother’s reaction wasn’t right. He was trying hard to act casual, but when he had first seen Percy, Hazel had noticed his momentary look of panic. Nico already knew Percy. She was sure of it.
*** Most likely the reasons behind it will be explained in later books since it seems like Nico is doing stuff behind the scenes that may be questionable
*** Mark of Athena confirms that Hades led Nico to the Roman Camp, but made him promise never to reveal it to anyone he knew.

* If the Greek demigods want the Romans to trust them and let the warship land, why not have Jason send a message instead of Leo?
** Maybe the monster plaguing them since Georgia are keeping him busy. What, ya think four demis in a floating ship are going to be stealthy flying to California?
*** Please clarify, I don't remember anyone being in or from Georgia and how would that prevent Jason from sending a message from the warship?
** It's possible that Jason thought, if he sent a message, it could be misinterpreted- especially if he remembered Octavian and how he manipulated things. It wouldn't be impossible for Jason to make a slip of the tongue, or just saying things in a certain tone (like 'I'm with my friends, and we're coming to see you' said in a slightly panicked voice for a different reason, like moving air currents or an engine problem) that Octavian 'interprets' as him being in a hostage situation, and using it to turn the Romans against the Greeks.
** Plus, as they were coming as representatives, it makes more sense for a Greek Demi God to send the message.

* If Hazel is [[ReallySevenHundredYearsOld mentally really seventy years old]], does that mean Frank LikesOlderWomen?
** interesting, [[spoiler: but she did expend most of that time in the fields of asphodel]]
** She's not "mentally seventy"; she died as a teenager and thus kept the consciousness of one for the rest of her [after]life.

* I'm a bit confused about Queen Marie's involvement of "cursing" Hazel. It looks like Hazel's gems and mineral treasures are cursed because of her mother's greed and wish for great wealth. But why did her wish have to present itself in the form of her daughter? The book makes it seem like it was Pluto's direct influence that gave her her powers rather than genetics like every other demigod, so why would Pluto curse his own daughter? Surely he could have given Marie a way of getting his wealth without bringing Hazel into it or making it cursed.
** In Greek myths, asking for something incredible from a god always ends badly. The example that comes to mind is King Midas, who asked for all the gold in the world.
*** Still, manifesting her wish as a curse for his own daughter is pretty dickish, even by Greek god standards.
** I got the implication that the stuff that came up was ''inherently'' cursed, as in, there was nothing Pluto could do to make it not be cursed.
** Also bear in mind that the Gods have knowledge of the future. So he most likely knew that Hazel would be part of the Prophecy of Seven and that those gifts would be needed.
** I'm not 100% with this, but in The Lost Hero, when Leo is talking to his dad, Hephaestus makes it seem like he knowingly gave Leo the power over fire. Maybe the Gods themselves can choose what their children get. Marie asked Pluto for that specific power, and he granted it, but the power itself is cursed.

* How great are the differences between the Roman and Greek versions? Some like Jupiter/Zeus and Boreas come across as so minor it is just a name change. Others like Mars/Ares and Juno/Hera are quite a bit different personality wise? How do they decide which one to go with if the two personalities clash? Or do the gods lack control over an aspect? Do the Roman versions probable have their own version of Olympus then?
** The Greek and Roman aspects are very different, according to what Frank said to Percy in SoN. Zeus wasn't very responsible in the original Greek myths; Jupiter, on the other hand, is - Thalia tells her brother Jason just how different their father was when he came back to "visit" (more stern, more fatherly towards Thalia - in other words, he was in his Roman aspect). As for the whole split-personality thing, Hephaestus tells Leo all about it in TLO. The gods are very powerful - it is rare for them to be in one place in full form. Do you remember the story where Semele asked to see Zeus in all his glory? She got zapped. It makes sense that the essence of a God/dess would not be in one place; all their attention is divided, thus the many demigods
** [[spoiler: And as indicated in ''Mark of Athena'', the differences become ''quite'' noticeable when the Greeks and Romans are at war: there's enough disconnect between the two aspects that it's incapacitating most of them (most notably Athena/Minerva).]]

* The fact that Minerva is stated to be not as important to the Romans as she was to Greeks. From what I remember Jupiter, Juno, and Minerva were worshipped as the Capitoline Triad, very important deities in the Roman capital. So, while yes, she became less of a war goddess (though in Rome itself she was still one, just not the rest of Italy), she was still extremely important to Roman culture.
** I think that its because that all the gods got an upgrade when Rome took over,while Athena got the short end of the stick. Remember that during the time of Ancient Greece, Athena was one of the most powerful and important god, next to Zeus and Posiedon. Jupiter became the most powerful, Mars and Venus being the Divine Parentage of Rome were elevated to high status. Because Rome depended on Farming and Bread than Greece which relied on Seafaring She become more powerful as well. Rome was well known as the lover of wine, so Dionysus got more powerful,and with the creation of Roman Road and commerce across three continents Hermes got more powerful as well. Even Hestia become a more major god in Rome. While Athena become nothing more than just a craftsman goddess. Also the Original Capitoline Triad was Jupiter, Mars and Quirinus(who was a god from Etruscan Mythology), Minerva become part of the Capitoline Triad to replace Quirinus who most likely faded just like Pan did.

* If Dionysus/Bacchus was a mortal during the first Gigantomachy, why did Gaea create Otis and Ephialtes to be the anti-Dionysus?
** Well i think that originally Otis and Ephialties were actually the Anti-Apollo and Anti-Artemis respectively, as they are both twins and were hunters in the book i read. Artemis tricks them into shooting each other with an arrow(which is {{FridgeBrilliance}} as while they can not be killed by gods or mortals, that doesn't mean they can't kill themselves.
** It is more a case of Riordan for radically changing the mythology. He has done a little in the past, but I think this may be the most major example. In myth, Hercules was the only recorded demigod to fight beside the Olympians. It was the whole reason he was born. Otis and Ephialties were part of a totally different rebellion thanks to being sons of Poseidon. They did not use illusions either. Dionysus had nothing to do with either myth. This was the only way Riordan could include the Bacchus or give a reason why more than one demigod was needed.
** From what this troper heard/read, Dionysus killed a giant named Eurytus, while Otis (Otus) and Ephialties were either killed by Apollo and Heracles OR tricked into killing each other. Why not have Eurytus as the wine-dude's destined foe?

* Son of Neptune makes it clear that all the prophecies are ancient and were originally in Latin. Why, then, do they still rhyme in English? And how are Octavian's translations word-for-word identical to the Oracle's. Also, some of the puns and double-meanings probably wouldn't work in both languages.
** Consider that the Gods have changed to English speakers, the monsters all speak English, and the demigods speak English (with the exception of children of Aphrodite, who are gifted with the ability to speak French as well, as it is the language of Love.) It then makes sense that as the portions of the mythology take on a new culture, so to do the writings from said culture. Thus, something from Greek or Latin is in itself 'transformed' into English because the nature it is based off of was transformed to English.
* Son of Neptune frequently brings up that, when they find him, Thanatos might kill Hazel and Frank. I get Hazel, but why would he kill Frank? He wasn't already dead, and they didn't know about the whole "fires of life" thing until they found him. His life being dependent on a stick doesn't make him dead.