Disclaimer: I am not Rick Riordan or George Lucas.
Here are the characters in this story:
Jason Grace - Jacen Solo (age 15), Imperial demigod
Piper McLean - Danni Quee (age 15), Jedi demigod
Leo Valdez - Ben Skywalker (age 15), Jedi demigod
Annabeth Chase - Mara Jade (age 16), Jedi demigod
Gleeson Hedge - Booster Terrik (age 104), Jedi recruiter
Thalia Grace - Jaina Solo (immortal), Witch of Dathomir
Khione - Nen Yim (immortal), Je'daii traitor
Rachel Dare - Gaeriel Captison (age 16), Jedi Prophet
Gaea - Abeloth (immortal), mastermind
Hera / Juno - Shira / Lumiya (immortal), Queen of Tython
Poseidon - Vader (immortal), King of Kamino (mention only)
Clarisse La Rue - Saba Sebatyne (age 17), Jedi demigod
Chiron - Yoda (immortal), director of the Jedi Praxeum
Hades - Bogan (immortal), King of the Netherworld (mention only)
Zeus / Jupiter - Sekot / Zonama (immortal), King of Tython (mention only)
Ares - Yun-Yammka (immortal), god of war (mention only)
Hermes - Yun-Shuno (immortal), goddess of thieves (mention only)
Demeter - Anima (immortal), goddess of fertility (mention only)
Dionysus "Mr. D" - Qel-Droma "Master Q" (immortal), god of wine (mention only)
Drew Tanaka - Erisi Dlarit (age 16), Jedi demigod
Silena Beauregard - Seha Dorvald (deceased), Jedi martyr (mention only)
Sally Jackson - Shmi Skywalker (age 44), mother of Luke Skywalker (mention only)
Porphyrion - Shimrra (immortal), Supreme Overlord of the Yuuzhan Vong
Charles Beckondorf - Ganner Rhysode (deceased), Jedi martyr (mention only)
Lupa - Vergere (immortal), Imperial instructor
Tristan McLean - Face Loran (age 39), actor
Travis Stoll - Chak Fel (age 16), Jedi demigod
Medea - Alema Rar (deceased), witch
Enceladus - Onimi (immortal), Yuuzhan Vong
Lou Ellen - Numa Rar (age 16), Jedi demigod
Argus - Jurokk (immortal), Jedi sentry
Festus - Falcon (age unknown), mechanical dragon
Aeolus - UnuThul (immortal), Lord of the Winds
Boreas / Aquilon - Thrawn / Mith'raw'nuruodo (immortal), god of winter
Lacy - Lyric (age 11), Jedi demigod
Butch Walker - Zekk (age 16), Jedi demigod
Tempest - World Brain (amortal), dhuryam
Mellie - Jysella (age unknown), Melodie
Esperanza Valdez - Leia Amidala Skywalker (deceased), mother of Ben Skywalker
Kronos - Palpatine (immortal), Sith Emperor (mention only)
Percy Jackson - Luke Skywalker (age 16), Jedi demigod (mention only)
Grover Underwood - Corran Horn (age 32), Lord of the Wild (mention only)
Peleus - Rancor (immortal), guardian of the Healing Crystals of Fire
Mitchell - Miko Reglia (age 16), Jedi demigod
Zethes - Thrass (immortal), former Revanchist
Clovis - Fi Skirata (age 15), Jedi demigod
Athena - Ashla (immortal), goddess of wisdom and war (mention only)
Apollo - Yavin (immortal), god of prophecy (mention only)
Artemis - Dathomir (immortal), goddess of the hunt (mention only)
Hephaestus - Yun-Ne'Shel (immortal), god of fire
Aphrodite - Yun-Q'aah (immortal), goddess of love
Hercules - (Anakin) Skywalker (immortal), god of heroes (mention only)
Calais - Drask (immortal), former Revanchist
Will Solace - Dorsk 81 (age 16), Jedi demigod and healer
Krios - Darth Krayt (immortal), Sith Lord and defender of Korriban (mention only)
Nyssa Barerra - Daeshara'cor (age 16), Jedi demigod
Lycaon - Darth Scabrous (immortal), lycanthrope
Midas - Zsinj (deceased), king
Jason - Jacen (deceased), Republic hero (mention only)
Dylan - Welk (amortal), Force spirit
Ma Gasket - Mezhan Kwaad (immortal), weapons manufacturer for the Yuuzhan Vong
Harley - Liam (age 8), Jedi demigod
Miranda Gardiner - Jesmin Tainer (age 15), Jedi demigod
Lityerses - Kas'im (deceased), swordsman
Zoë - Lara Notsil (deceased), daughter of Zsinj
Thomas McLean - Garik Loran (deceased), grandfather of Danni Quee (mention only)
Jane - Viqi Shesh (age 41), brainwashed Yuuzhan Vong conspirator
Christopher - Raynar Thul (age 17), Jedi demigod
Shane - Cem Fel (age 16), Jedi demigod
Seymour - Cay (age unknown), sabercat
Typhon - Nyax (immortal), storm giant (mention only)
Torque - Krayn (immortal), weapons manufacturer for the Yuuzhan Vong
Sump - Rashtah (immortal), weapons manufacturer for the Yuuzhan Vong
Jake Mason - Kenth Hamner (age 16), Jedi demigod
Phoebe - Kirana Ti (immortal), Witch of Dathomir
Damien White - Todr Fel (age 16), Jedi demigod
Laurel Victor - Tavia Kitik (age 15), Jedi demigod
Holly Victor - Bink Kitik (age 15), Jedi demigod
Paolo Montes - Zak Arranda (age 14), Jedi demigod
Chiara Benvenuti - Ajai Fel (age 16), Jedi demigod
Reyna Ramirez-Arellano - Tenel Ka Djo (age 15), Grand Admiral of the Imperial Remnant (mention only)
Gwendolyn - Etain Tur-Mukan (age 16), Imperial demigod and general (mention only)
Hazel Levesque - Tahiri Veila (age 13), Imperial demigod (mention only)
Dakota - Wedge Antilles (age 16), Imperial demigod and general (mention only)
Bobby - Wes Janson (age 16), Imperial demigod (mention only)
Luke Castellan - Jacen (Solo) Caedus (deceased), redeemed Sith minion (mention only)
Nico di Angelo - Kyp Durron (age 12), Jedi demigod (mention only)
Hecate - Morag (immortal), Sith minion (mention only)
Hebe - Aldera (immortal), Sith minion (mention only)
Nemesis - Yun-Harla (immortal), Sith minion (mention only)
Hypnos / Somnus - Morichro / Nathema (immortal), god of sleep (mention only)
Aeneas - Jax Pavan (deceased), Imperial demigod (mention only)
Rosa Valdez - Rouge Organa (deceased), sister to Leia Amidala Skywalker
Frank Zhang - Jagged Fel (age 15), Imperial demigod (indirect mention only)
Locations:
Camp Half-Blood - Jedi Praxeum (Big House - Jedi Temple)
Camp Jupiter - Imperial Remnant (mention only)
California - Outer Rim (San Francisco - Braxant sector)
Berkeley - Sartinaynian
The Underworld - The Netherworld of the Force (mention only)
Fields of Punishment - Chaos (mention only)
Chicago - Alsakan
Quebec - Csilla
Olympus - Tython (mention only)
New York - Coruscant (Long Island - Centax)
Princess Andromeda - Anakin Solo (mention only)
Othrys - Korriban (mention only)
Manhattan - Galactic City
Mount Diablo - Shimrra's Citadel
Oklahoma - Pantolomin
Texas (Houston) - Tatooine (Anchorhead)
Colorado (Pikes Peak) - Utegetu Nebula (Woteba)
Wolf House - Baanu Rass
Argo II - Millennium Falcon
Species:
Human - Human (Mortal - Mundane)
Satyr (Faun) - Corellian (Ryn)
Olympian - Je'daii
Gigantes - Yuuzhan Vong
Titan - Sith (mention only)
Centaur - Chironian
Cyclops - Wookiee
Dracanae - Killik (mention only)
Pegasus - Aiwha
Earthborn - Rakghoul
Harpy - Omwati
Aura - Melodie
Hunters of Artemis - Witches of Dathomir
Wolf - Rancor
Automaton - Droid
Anemoi - Joiner
Anemoi thuelae / Ventus - Pazhkic Yuuzhan'tar al'tirrna / Dhuryam
Argonaut - Revanchist
Boread - Chiss
Lycanthrope - Shistavanen
Protogenoi - Celestials