Found in the backpack of a corpse on a battlefield, hopefully many years from the date of its creation:

Dear Diary, Hello! I found this book in the backpack I was given. I have also been assigned the name Gareth and given several things to wear. I can’t complain. I have not been ordered to complain. I am carrying several things, but I am not tired. Today I almost got to sweep up a chemical spill, but then the order was rescinded. Until next time, Gareth.

Dear Diary, Lord Olethros has brought me to a cave. I got to pick up some potatoes and I knocked over a kobold. Then Lord Olethros conjured the powers of (name redacted) to lay waste to his foes. I have not been ordered to be proud of myself, but I would be. As I write this, the plucky man is going to open a door. I sure hope not to get accidentally hewn by an orcish axe. Until next time, Gareth. 

Dear Diary, Hello! I found this book in the backpack I was given. I have also been assigned the name Gareth and given several things to wear. Today I got to copy a flyer several times for distribution to the future minions/victims of Lord Olethros. He has told me to make sure I keep a professional attitude. I will do my best. Until next time, Gareth. 

Dear Diary, Lord Olethros has brought me to a cave. I have been helping the current minions/future victims of Lord Olethros in their construction of a mighty bastion for the glory of (name redacted). Today I got to nail a board to a wall, and it was another hour before Lord Olethros returned to tell me to stop. That board will not be moving any time soon. Tomorrow we will be entering some rooms below the tomb we are in now. I have not been ordered to be excited about what we may find. Until next time, Gareth. 

Dear Diary, Today I got to rend the life from a vile enemy of (name redacted) and a foe of Lord Olethros. The large bird following the bearded lady has defecated upon the shoulder of the tuxedo I was given, but I have not yet been ordered to clean it. One foe has escaped and must be pursued. Until next time, Gareth. 

Dear Diary, Hello! I found this book in the backpack I was given. I have also been assigned the name Gareth and given several things to wear. The tuxedo appears to be damaged, but I have been ordered to mend it. Lord Olethros is pleased with himself and has given me some coins to carry. I am fulfilling my purpose to the best of my ability. Until next time, Gareth

Mythological Headcanons
  • Chaos is a woman. Repeat after me: Chaos is a woman. Particularly in Percy Jackson fanfiction, Chaos is usually written as a guy, but… that makes literally no sense at all? Sure, technically there isn’t a gender attached to the “great abyss that gave birth to the universe”, but that is literally the description of the first womb, how could Chaos not be the mother of the universe…?
  • Perseis is just a cool pseudonym Hecate gave herself. They are “closely identified” as each other, but most still call Perseis a nymph. That doesn’t add up for me. Perseis is the mother and grandmother of literally the greatest sorceresses and sorcerer - Circe, Pasiphae (mother of Ariadne, you remember the chick with her enchanted magic garn) and Aeetes (father of Medea, the kick-ass witch girlfriend of Jason). Them being the kids of the literal goddess of magic makes far more sense than an Oceanid nymph
  • Thanatos/Triton. Because Triton got all those daughters but not a single one has a mom. And hey - in mythology mpreg is actually canon, especially related to water deities (Poseidon/Nerites made a baby together despite both being men, the Egyptians got the fertility and water god Wadj-wer who’s portrayed as a pregnant man), so it’s actually not really that far-fetched that Triton and his male lover could be the parents of the Tritonides. And those two are my favorite non-canon gays for mythology
  • Harmonia/Eris. Because Eris has a gazillion kids and not a single one has a dad. So my favorite non-canon lesbians had some magic going on and made a gazillion kids together
  • Hades/Persephone are happy and in love. I know there are people who insist on the abduction part of their storry, but sorry the Beast held Belle captive too and everybody adores their fairy tale. There’s no way she didn’t fall in love with him too. She’s the goddess who has probably the most influence over her husband (-> making him allow Orpheus to take back Eurydice’s soul), they’re the most monogamous godly couple in Greek mythology, only having children with each other (aside from that one time Zeus raped Persephone and Dionysus 1.0 was born), he had no affairs, no mortal kids causing trouble, no gazillion godly kids from other mothers. Nope, those two only had eyes for each other. They’re happy. They’re my mythological OTP
  • Until the Big Three took over, Aether/Hemera ruled Olympus and Erebus/Nyx the underworld. When things changed, Erebus/Nyx retired to Tartarus but not without teaching Hades how everything worked. Because I like the idea of teen!Hades not sitting all alone in the underworld all the time but having mentors who look after him
  • Hades has his own counter-part to the Olympian council. A la “If you won’t have me, I’ll open my own club!”, with the most significant gods of the underworld in it (Hades, Persephone, Makaria, Melinoe, Thanatos, Olethros, Morpheus, Hypnos, Horkos, Hecate, Nemesis, Eris)
  • Hades and Hel meet up in the godly dog-park to take Zerberus and Garm out and gossip about the dead, sometimes Anubis joins them but being half-dog himself, he kind of takes offense to the other two having pet dogs
  • Hermes has regular poker-nights with Loki, Gwyddion fab Don and Seth - and no pantheon is happy about those, because they usually end with the tricksters drunk and pranking every god who crosses their way
  • among the children of Zeus, the following share a particularly close bond: Apollo and Artemis of course, Ares and Enyo also obviously, Persepohne and Dionysus, Hebe and Eleithyia
  • Aphrodite and Aglaia are bffs who have regular spa-days. I know bitter!Hephaestus is A Thing, but the dude found another goddess of beauty who actually loves him so, I dunno, I wouldn’t cry a tear for Aphrodite, who keeps cheating around? But I definitely think the goddess of love played a big role in Hephaestus and Aglaia getting together, maybe because she felt bad for how things went down
  • Zeus and Thor are bros who hang out, drink a lot and have lightning-throwing competitions
  • Hera and Frigga are bffs who meet up for tea parties and to bitch about their unfaithful husbands who keep dropping off illegitimate children in their laps
  • Rhea and Don are bffs who bemoan how hard it is to be a mother goddess, especially with the shit their brats get up to
  • Artemis and Skadi are bffs who meet up for hunting sessions together
  • Apollo and Frey are bffs and they’re pretty much useless when they meet up because deep down, they’re both total dorks who just like to enjoy a sunny day, wax poetry and watch pretty people
  • Freya and Bastet are bffs who regularly meet up to kick people’s asses (usually, the boys like Ares “volunteer” by being idiots)
  • Eros and Aonghus are bros who love to write smut-fics together
  • Sleipnir and Arion have regular races to see who’s the fastest. They always end in a draw
  • Robin Hood is a Celtic demigod son of Lugh, god of tricksters and thieves

Aaand as you can see, most of my headcanons are Greek/Norse crossovers. Which is kind of the reason I’m not gonna touch Magnus Chase, because I have too many precious headcanons about the Norse gods to let Riordan destroy them also I stopped trusting him with Blood of Olympus