Disclaimer: I am not Rick Riordan or George Lucas.
Here are the characters in this story:
Percy "Seaweed Brain" Jackson - Luke "Farmboy" Skywalker (age 15), Jedi demigod
Annabeth Chase - Mara Jade (age 15), Jedi demigod
Grover Underwood - Corran Horn (age 31), Corellian searcher
Tyson - Lowbacca (age 14), Wookiee
Rachel Dare - Gaeriel Captison (age 15), clairvoyant
Poseidon - Vader (immortal), King of Kamino
Luke Castellan - Jacen (Solo) Caedus (age 22), Sith minion and captain of the Anakin Solo
Bianca di Angelo - Ahsoka (Tano) Durron (deceased), Witch of Dathomir
Nico di Angelo - Kyp Durron (age 11), fugitive
Clarisse La Rue - Saba Sebatyne (age 16), Jedi demigod
Zoë Nightshade - Akanah Norand Goss (deceased), Witch of Dathomir (mention only)
Hades - Bogan (immortal), King of the Netherworld (mention only)
Zeus - Sekot (immortal), King of Tython (mention only)
Kronos - Palpatine (immortal), Sith Emperor
Ares - Yun-Yammka (immortal), god of war (mention only)
Hermes - Yun-Shuno (immortal), god of thieves (mention only)
Demeter - Anima (immortal), goddess of fertility (mention only)
Dionysus "Mr. D" - Qel-Droma "Master Q" (immortal), director of the Jedi Praxeum
Calypso - Vestara Khai (immortal), witch
Chiron - Yoda (immortal), Jedi instructor
Silena Beauregard - Seha Dorvald (age 18), Jedi demigod
Sally Jackson - Shmi Skywalker (age 43), mother of Luke Skywalker
Oracle of Delphi - Prophet of Yavin (immortal), Jedi Seer (mention only)
Charles Beckondorf - Ganner Rhysode (age 18), Jedi demigod
Atlas - Dooku (immortal), Sith Lord (mention only)
Paul Blofis - Ben Kenobi (age 43), teacher
Travis Stoll - Chak Fel (age 15), Jedi demigod
Connor Stoll - Davin Fel (age 16), Jedi demigod
Chris Rodriguez - Raynar Thul (age 16), former Sith minion
Ethan Nakamura - Soontir Fel (age 15), Sith minion
Argus - Jurokk (immortal), Jedi sentry
Blackjack - R2-D2 (age unknown), aiwha
Mrs. O'Leary - Drang (immortal), vornskr
Ariadne - Nomi Sunrider (immortal), goddess of labyrinths (mention only)
Pan - Yu'shaa (immortal), Lord of the Wild
Daedalus / Quintus - Vodo Siosk-Baas / Nichos Marr (age unknown), creator of the Graveyard and Jedi battlemaster
Kelli - Nikkos Tyris (immortal), Sith minion
Michael Yew - Tekli (age 15), Jedi demigod
Juniper - Mirax (age unknown), Melodie
Peleus - Rancor (immortal), guardian of the Healing Crystals of Fire
Kampé - Ysanne Isard (immortal), warden at Lusankya
Janus - Darth Bane (immortal), Je'daii traitor
Briares - Chewbacca (immortal), Wookiee hero
Hera - Shira (immortal), Queen of Tython
Athena - Ashla (immortal), goddess of wisdom and war
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 (mention only)
Hercules - (Anakin) Skywalker (immortal), god of heroes (mention only)
Cocalus - Arca Jeth (deceased), King of Onderon
Aelia - Krynda Draay (deceased), princess
Lee Fletcher - Ton Phanan (age 16), Jedi demigod
Antaeus - Sarasu Taalon (immortal), giant
Porkpie - Arnie (age unknown), aiwha
Guido - Sneaky (age unknown), aiwha
Geryon - Kueller (immortal), monster
Castor - Biggs Darklighter (age 16), Jedi demigod
Pollux - Gavin Darklighter (age 16), Jedi demigod
Theseus - Andur Sunrider (deceased), Jedi demigod
Malcolm Pace - Kyle Katarn (age 15), Jedi demigod
Minos - Exar Kun (deceased), Sith spirit
Sphinx - Waru (immortal), monster
Eurytion - Brakiss (immortal), demigod
Orthus - Sturm (immortal), vornskr
Tammi - Kell Douro (immortal), Sith minion
Leneus - Garm Bel Iblis (age unknown), Corellian leader
Perdix - Cray Mingla (deceased), niece of Vodo Siosk-Baas
Icarus - Bodo Baas (deceased), son of Vodo Siosk-Baas
Silenus - Thame Cerulian (age unknown), Corellian leader
Maron - Dur Gejjen (age unknown), Corellian leader
Typhon - Nyax (immortal), storm giant (mention only)
Gaea - Abeloth (immortal), mastermind (mention only)
Diomedes - Miraj Scintel (deceased), queen (mention only)
Medusa - Garowyn (deceased), Dathomirian (mention only)
Circe - Talzin (immortal), witch (mention only)
Locations:
Camp Half-Blood - Jedi Praxeum (Big House - Jedi Temple)
The Underworld - The Netherworld of the Force
Olympus - Tython (mention only)
New York - Coruscant (Long Island - Centax)
Goode High School - Ossus Academy
Princess Andromeda - Anakin Solo
Othrys - Korriban
The Labyrinth - The Graveyard
Manhattan - Galactic City
Alcatraz - Lusankya
Ogygia - Mortis
Triple G Ranch - Almania
Crete - Empress Teta (mention only)
Species:
Human - Human (Mortal - Mundane)
Satyr - Corellian
Olympian - Je'daii
Titan - Sith
Centaur - Chironian
Cyclops - Wookiee
Dracanae - Killik
Pegasus - Aiwha
Hippocampus - Varactyl
Fire-breathing horse - Fire Breather
Mares of Diomedes - Cherfer
Hippalektryon - Ronto
Laestrygonian - Gundark
Harpy - Omwati
Empousa - Anzati
Telekhine - Noghri
Nereid - Kaminoan
Dryad - Melodie
Hesperid - Mistryl Shadow Guard (mention only)
Hunters of Artemis - Witches of Dathomir (mention only)
Hellhound - Vornskr
Automaton - Droid
Protogenoi - Celestials (mention only)