Disclaimer: I am not Rick Riordan or George Lucas.
Here are the characters in this story:
Percy "Seaweed Brain" Jackson - Luke "Farmboy" Skywalker (age 16), Jedi demigod
Annabeth Chase - Mara Jade (age 16), Jedi demigod
Grover Underwood - Corran Horn (age 32), Lord of the Wild
Tyson - Lowbacca (age 15), Wookiee
Rachel Dare - Gaeriel Captison (age 16), clairvoyant
Poseidon - Vader (immortal), King of Kamino
Luke Castellan - Jacen (Solo) Caedus (age 23), Sith Emperor and captain of the Anakin Solo
Bianca di Angelo - Ahsoka (Tano) Durron (deceased), Witch of Dathomir
Nico di Angelo - Kyp Durron (age 12), Jedi demigod
Clarisse La Rue - Saba Sebatyne (age 17), Jedi demigod
Thalia Grace - Jaina Solo (immortal), Witch of Dathomir
Hades - Bogan (immortal), King of the Netherworld
Zeus - Sekot (immortal), King of Tython
Kronos - Palpatine (immortal), Sith Emperor
Ares - Yun-Yammka (immortal), god of war
Hermes - Yun-Shuno (immortal), goddess of thieves
Demeter - Anima (immortal), goddess of fertility
Dionysus "Mr. D" - Qel-Droma "Master Q" (immortal), director of the Jedi Praxeum
Hestia - Jabitha (immortal), goddess of the hearth
Chiron - Yoda (immortal), Jedi instructor
Silena Beauregard - Seha Dorvald (age 19), Sith spy
Sally Jackson - Shmi Skywalker (age 44), mother of Luke Skywalker
Oracle of Delphi - Prophet of Yavin (immortal), Jedi Seer
Charles Beckondorf - Ganner Rhysode (age 19), Jedi demigod
Atlas - Dooku (immortal), Sith Lord
Paul Blofis - Ben Kenobi (age 44), teacher
Travis Stoll - Chak Fel (age 16), Jedi demigod
Connor Stoll - Davin Fel (age 17), Jedi demigod
Chris Rodriguez - Raynar Thul (age 17), Jedi demigod
Ethan Nakamura - Soontir Fel (age 16), Sith minion
Argus - Jurokk (immortal), Jedi sentry
Blackjack - R2-D2 (age unknown), aiwha
Mrs. O'Leary - Drang (immortal), vornskr
Persephone - Githany (immortal), Queen of the Netherworld
Pan - Yu'shaa (immortal), Lord of the Wild (mention only)
Daedalus - Vodo Siosk-Baas (deceased), creator of the Graveyard (mention only)
Amphitrite - Amidala (immortal), Queen of Kamino
Michael Yew - Tekli (age 16), Jedi demigod
Juniper - Mirax (age unknown), Melodie
Peleus - Rancor (immortal), guardian of the Healing Crystals of Fire
Hyperion - Hethrir (immortal), Sith Lord
Janus - Darth Bane (immortal), Sith minion (mention only)
Triton - Starkiller (immortal), Prince of Kamino
Hera - Shira (immortal), Queen of Tython
Athena - Ashla (immortal), goddess of wisdom and war
Apollo - Yavin (immortal), god of prophecy
Artemis - Dathomir (immortal), goddess of the hunt
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)
Gleeson Hedge - Booster Terrik (age 104), Jedi recruiter (mention only)
Oceanus - Darth Malak (immortal), Sith Lord and former King of Kamino
Will Solace - Dorsk 81 (age 16), Jedi demigod and healer
Krios - Darth Krayt (immortal), Sith Lord and defender of Korriban
Ophiotaurus - Ikrit (immortal), bane of Tython
Castor - Biggs Darklighter (deceased), Jedi demigod (mention only)
Pollux - Gavin Darklighter (age 17), Jedi demigod
Theseus - Andur Sunrider (deceased), Jedi demigod (mention only)
Malcolm Pace - Kyle Katarn (age 16), Jedi demigod
Prometheus - Darth Malgus (immortal), Sith Lord
Katie Gardner - Tyria Sarkin (age 15), Jedi demigod
Alecto "Mrs. Dodds" - Asajj "Madam Ventress" (immortal), Nightsister
Morpheus - Jerec (immortal), Sith minion (mention only)
Maria di Angelo - Vima (-Da-Boda) Durron (deceased), mother of Kyp Durron
Leneus - Garm Bel Iblis (age unknown), Corellian leader
Koios - Skere Kaan (immortal), Sith Lord (unmentioned)
Briares - Chewbacca (immortal), Wookiee hero
May Castellan - Den (Solo) Caedus (age 52), father of Jacen Caedus
Achilles - Quinlan Vos (deceased), Jedi demigod
Typhon - Nyax (immortal), storm giant
Echidna - Roganda (immortal), monster (mention only)
Gaea - Abeloth (immortal), mastermind (mention only)
Minotaur - Gamorrean (immortal), monster
Cerberus - Tuk'ata (immortal), guardian of the Netherworld
Jake Mason - Kenth Hamner (age 16), Jedi demigod
Phoebe - Kirana Ti (immortal), Witch of Dathomir
Elpis - Tutaminis (immortal), goddess of hope
Austin Lake - Bardan Jusik (age 12), Jedi demigod
Kayla Knowles - Barriss Offee (age 11), Jedi demigod
Aeolus - UnuThul (immortal), Lord of the Winds (mention only)
Boreas - Thrawn (immortal), god of winter
Notus - Kinetite (immortal), god of summer
Zephyros - Ferus Olin (immortal), god of spring
Clazmonian sow - Kashyyyk can-cell
Rainbow - Boga (age unknown), varactyl
Pomona - Yaddle (immortal), Sith minion
Delphin - Nahdar Vebb (immortal), Kaminoan lieutenant
Ferdinand - Halcyon (deceased), former Corellian searcher
Mark - Tesar Sebatyne (age 16), Jedi demigod
Sherman Yang - Bela Hara (age 15), Jedi demigod
George - Han (immortal), amphistaff
Martha - Leia (immortal), amphistaff
Megaera - Gethzerion (immortal), Nightsister
Tisiphone - Talia (immortal), Nightsister
Palaemon - Riff Tamson (immortal), Kaminoan lieutenant
Mr. Dare - Dol Captison (age 45), father of Gaeriel Captison
Porkpie - Arnie (age unknown), aiwha
Guido - Sneaky (age unknown), aiwha
Sess - Gorog (age unknown), Queen of the Killiks
East - Great Western (immortal), god of the Great Western Sea
Hudson - Solleu (immortal), god of the Solleu River
Cancer - Vonduun (immortal), monster
Morrain - Hue (age unknown), Sith minion
Mrs. Dare - Madam Captison (age 45), mother of Gaeriel Captison
Owen - Lusa (age unknown), Chironian
Larry - Wicket (age unknown), Chironian
William H. Seward - Carlist Rieekan (deceased), Jedi demigod
Hecate - Morag (immortal), Sith minion (mention only)
Hebe - Aldera (immortal), Sith minion (mention only)
Nemesis - Yun-Harla (immortal), Sith minion (mention only)
Jason Grace - Jacen Solo (age 15), Imperial demigod (indirect mention only)
Piper McLean - Danni Quee (age 15), Jedi demigod (indirect mention only)
Leo Valdez - Ben Skywalker (age 15), Jedi demigod (indirect mention only)
Hazel Levesque - Tahiri Veila (deceased), Imperial demigod (indirect mention only)
Frank Zhang - Jagged Fel (age 15), Imperial demigod (indirect mention only)
Thanatos - Xanatos (immortal), god of death (mention only)
Locations:
Camp Half-Blood - Jedi Praxeum (Big House - Jedi Temple)
The Underworld - The Netherworld of the Force
Fields of Punishment - Chaos
Elysium - Alderaan
Isles of Blest - Zonama Sekot
Olympus - Tython (Hall of the Gods - Je'daii High Council Chamber)
New York - Coruscant (Long Island - Centax)
Goode High School - Ossus Academy (mention only)
Princess Andromeda - Anakin Solo
Othrys - Korriban
East River - Great Western Sea
Hudson River - Solleu River
Manhattan - Galactic City
Connecticut - New Alderaan
Species:
Human - Human (Mortal - Mundane)
Satyr - Corellian
Olympian - Je'daii
Titan - Sith
Centaur - Chironian
Cyclops - Wookiee
Dracanae - Killik
Pegasus - Aiwha
Hippocampus - Varactyl
Laestrygonian - Gundark
Harpy - Omwati
Telekhine - Noghri
Nereid - Kaminoan
Dryad - Melodie
Hyperborean - Phlog
Hunters of Artemis - Witches of Dathomir
Hellhound - Vornskr
Automaton - Droid
Erinyes - Nightsisters
The Fates - The Force
Merperson - Kaminoan
Lydian drakon - Coruscanti Taozin
Anemoi - Joiner
Empousa - Anzati
Protogenoi - Celestials (mention only)