Disclaimer: I am not Rick Riordan or George Lucas.
Here are the characters in this story:
Percy "Seaweed Brain" Jackson - Luke "Farmboy" Skywalker (age 13), Jedi demigod
Annabeth Chase - Mara Jade (age 13), Jedi demigod
Poseidon - Vader (immortal), King of Kamino (mention only)
Luke Castellan - Jacen (Solo) Caedus (age 20), Sith minion and captain of the Anakin Solo
Clarisse La Rue - Saba Sebatyne (age 14), Jedi demigod
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)
Grover Underwood - Corran Horn (age 29), prisoner
Hermes - Yun-Shuno (immortal), goddess of thieves
Demeter - Anima (immortal), goddess of fertility (mention only)
Dionysus "Mr. D" - Qel-Droma "Master Q" (immortal), director of the Jedi Praxeum
Tyson - Lowbacca (age 12), Wookiee
Chiron - Yoda (immortal), Jedi instructor
Silena Beauregard - Seha Dorvald (age 16), Jedi demigod
Sally Jackson - Shmi Skywalker (age 41), mother of Luke Skywalker
Oracle of Delphi - Prophet of Yavin (immortal), Jedi Seer (mention only)
Thalia Grace - Jaina Solo (age 18), Jedi demigod
Chris Rodriguez - Raynar Thul (age 14), Sith minion
Charles Beckondorf - Ganner Rhysode (age 16), Jedi demigod
Circe - Talzin (immortal), witch
Charybdis - Sarlacc (immortal), guardian of the Unknown Regions
Travis Stoll - Chak Fel (age 14), Jedi demigod
Connor Stoll - Davin Fel (age 15), Jedi demigod
Frederick Chase - (Talon) Karrde Jade (age 45), father of Mara Jade (mention only)
Hylla Ramirez-Arellano - Teneniel Djo (age 17), handmaiden of Talzin
Argus - Jurokk (immortal), Jedi sentry
Blackjack - R2-D2 (age unknown), aiwha
Anger - Enara (immortal), Fallanassi
Tempest - Eliya (immortal), Fallanassi
Wasp - Nashira (immortal), Fallanassi
Polyphemus - Monarg (immortal), Wookiee
Scylla - Acklay (immortal), guardian of the Unknown Regions
Tantalus - Qordis (deceased), enemy of the Je'daii
Hydra - Zillo Beast (immortal), monster
Peleus - Rancor (immortal), guardian of the Healing Crystals of Fire
Agrius - Muuurgh (immortal), Sith minion
Orieus - H'sishi (immortal), Sith minion
Edward "Blackbeard" Teach - Tyber Zann (age 327), prisoner
Hera - Shira (immortal), Queen of Tython (mention only)
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 (mention only)
Aphrodite - Yun-Q'aah (immortal), goddess of love (mention only)
Hercules -(Anakin) Skywalker (immortal), god of heroes (mention only)
Rainbow - Boga (age unknown), varactyl
George - Han (immortal), amphistaff
Martha - Leia (immortal), amphistaff
Matt Sloan - Windy Starkiller (age 13), student at Tosche Station
Bonsai - Fixer (age 34), headmaster
Nunley - Watto (age 70), coach
Raj Mandali - Deacon (age 13), student at Tosche Station
Corey Bailer - Tank Sunber (age 13), student at Tosche Station
Jason - Jacen (deceased), Republic hero (mention only)
Pegasus - Aiwha (immortal), god of the aiwha (mention only)
Locations:
Camp Half-Blood - Jedi Praxeum (Big House - Jedi Temple)
The Underworld - The Netherworld of the Force (mention only)
Fields of Punishment - Chaos (mention only)
Sea of Monsters - Unknown Regions
Circe's Island - Dathomir
Polyphemus's Island - Monarg's Mechanic Works
Island of the Sirens - Moons of Iego
Olympus - Tython (mention only)
New York - Coruscant (Long Island - Centax)
Meriwether Prep - Tosche Station
Princess Andromeda - Anakin Solo
Florida - Chiron
Manhattan - Galactic City
Colchis - Basilisk (mention only)
Species:
Human - Human (Mortal - Mundane)
Satyr - Corellian
Olympian - Je'daii
Titan - Sith
Centaur - Chironian
Cyclops - Wookiee
Graeae - Fallanassi
Pegasus - Aiwha
Hippocampus - Varactyl
Laestrygonian - Gundark
Harpy - Omwati
Siren - Diathim
Nereid - Kaminoan
Naiad - Melodie
Stymphalian - Hawk-bat
Dracanae - Killik
Bear Twin - Togorian
Colchis bull - Basilisk war droid