Prologue

Lord Arceus watches over a little girl and her mother in another dimension, horrified, as Sally Jackson, lover of Poseidon, the Greco-Roman Sea God in that dimension, dies to save her daughter Precosia from a horde of monsters. He knew of the rules that bound Poseidon from coming to his daughter's aid. Precosia Jackson had a destiny ahead of her but, first, she had to survive. The six year old would join his Chosen One on his journey until it was time for her to return home.

She would be raised on Valencia Island and travel to Pallet Town to register as a Pokémon Trainer so she would hopefully meet his Chosen One then. Now he just had to decide on what her starter pokémon would be.

Clotho, Lachesis, and Atropa stare as Precosia Jackson's fate is taken out of their hands by a higher power than them. They dare not mess with Lord Arceus, if he was interceding on behalf of Poseidon's only demigoddess daughter then there was nothing they could do. They're also stunned when Mew shows up and lets them know in no uncertain terms are they to inform any of the Olympians, major or minor.

Chapter One

Precosia Jackson of Valencia Island looks around Pallet Town in wonder, this was the furthest she had ever been from Valencia Island. On her shoulder sat her Wingull, Ventina. Her sea green eyes show a sense of adventure and mischief. She'd won Ventina in a contest as an egg and she'd hatched three weeks ago. On top of the egg case she had come in there had been a Premier Ball, which was essentially all white, to catch Ventina in. In that same contest she had won 20 each of Lure Balls, Friend Balls, Heal Balls, Dark Balls, Quick Balls, Fast Balls, Moon Balls, and Heavy Balls.

She had a Pokégear, several Repels, Revives, Antidotes, Potions of all kinds, Burn Heal, Paralyze Heal, Freeze Heal, Awakening, a full Berry Case, all of the flutes, a Silph Scope, all three rods, the egg case Ventina had come in, a tent, a Kanto Field Guide, a lantern and fuel for it, a flint and steel, clothes and gear for all weathers and terrains, a sewing kit with material for patch jobs, towels, toiletries, human and pokémon vitamins, human and pokémon food, a compass, several herbs, including Salveo Weed tea, Pokémon Care books, wave stickers to put on her pokéballs, and normal Poké Balls.

She wore a white t-shirt with a blue trident on it, blue capris with white trim, she wore a blue backpack with a dark blue trident embroidered on it, a gift from her guardian on Valencia Island, this was a highly specialized back pack, and held much more than at first glance. A special belt that already had her Pokégear attached to it and would hold her pokéballs, it already held Ventina's. She wore dark blue fingerless gloves with light blue cuffs, sea green shoes with blue stripes, said shoes were strapped on. Her dark hair was back in a braid and had blue and sea green ribbons woven into it while she wore a bandana that looked like it had waves on it over her head. She had trident earrings in her ears with a matching necklace around her neck.

She makes her way to the lab, since she didn't need a starter she had been able to get there later. Precosia reaches the lab in time to see a Pikachu shock a young boy with messy black hair, brown eyes, and green and yellow pajamas, he must have overslept, " Ventina, please talk to that Pikachu and find out what the problem is. "

Ventina queries Pikachu and then translates for her mistress, yes, Precosia could understand any water pokémon whether they be dual typed or not, " I'm Precosia Jackson of Valencia Island, my Wingull, Ventina, tells me that Pikachu is feeling scared and doesn't like pokéballs. "

While Professor Oak registers her and Ventina as her starter she and Ventina negotiate a peace treaty between Ash and Pikachu, the boy had introduced himself after she had started the process. " Thanks for the help, Precosia. "

" No problem, Ash, thanks to my dad I can understand any and all water creatures. Lord Arceus rescued me from a different dimension and filled me in on my paternity, that's why I wear blue and the tridents, they're his symbol. Due to some ancient rules he wasn't allowed to even see me after I was born. " Precosia says softly.

" If you'll wait, I need to get changed, and we can travel together. " Ash says as Pikachu leaps up onto his shoulder.

" I'd like that, though make sure you pack gear for all weathers and terrains, not to mention know how to live off the land and you're toiletries. " Precosia says.

Ash nods, he'd done his research and had found a book about aura guardians one time when his mom had taken him to Viridian City. He'd had to have it and that was how he'd gotten his training as an aura guardian. He'd also made friends with a Shedinja that had been passing through. Once outside of Pallet Town with Precosia he pulses his aura and Shedinja comes to him. He pulls out a pokéball and catches his friend before letting him back out. Precosia had gone fishing while waiting on him and had caught a female Tentacool that she named Tethys and female Magikarp that she named Chalchuuhtlicue, named for the Aztec goddess of water, rivers, seas, lakes, streams, horizontal waters, storms, and baptisms. They'd both been caught in Lure Balls.

" I see you went fishing. "

" My dad's a water god. Of course, I am going to make sure I end up with a well balanced team, need each element represented after all. Besides, I want a Gyarados. "

Ash laughs at that response even as Ventina and Shedinja get to know each other, " How did you end up with a Sinnoh native anyhow? "

" Contest. " Precosia admits, her eyes were constantly roving, part of the whole demigoddess, ADHD shtick she had to deal with. Thankfully Lord Arceus had managed to get her half-brother Theseus to train her in sword play and mind play as well. He'd called in a favor with her Uncle Hades. This meant that she had the training she needed and Theseus had given her a trident that had been made by a daughter of Hephaestus, their cousin. It was perfectly well balanced and she was a master at using the trident. She had been told by Theseus how he had defeated every monster he had faced and the fact that once in their uncle's domain he had learned that they reformed.

Precosia was going to make sure she thanked every relevant deity in her home dimension, another reason she needed to get a fire pokémon. That way she could make her offerings properly. As they walk along Ash has the misfortune to kick a rock and hit a Spearow on the head. Precosia curses in Ancient Greek under her breath and spins on her heel, running. She recalls Ventina while Ash recalls Shedinja, then they kick in the afterburners, Pikachu's hanging on for dear life. Precosia grins when she sees the water, " Trust me, Ash. "

She knocks them off the cliff and concentrates on keeping them safe and dry, along with allowing them to breathe underwater. One thing about being a water god's kid, you had some pretty neat powers. Not drowning was one of them. Of course, the damn Spearow just had to be as stubborn as Zap Happy, Rich Dude, and Tide Surfer combined on a bad day. Precosia manages to get them to shore and she senses the storm that was brewing, she calls to it, giving it strength, building its power, hastening it along while at the same time surrounding them with a sphere of water.

She curses when she sees lightning, " Not good, water's a conductor of electricity. "

Ash was checking his pokédex, Dexter for information, " Pikachu, your ability is Lightning Rod, we need the water shield so you need to take the electrical attacks for us, can you do that? "

" Pika(On it)! " Pikachu says.

Somehow they managed to survive that and then the storm clears up and a rainbow appears. Precosia's eyes widen as they all look up and she was quick to grab her pokédex, Ariel and scan the giant bird, " Who's that Pokémon? "

Ariel replies, as Precosia had the Sinnoh region pokémon in her dex as well, " Ho-oh, legend claims that this Pokémon flies the world's skies in its magnificent seven-colored wings. A rainbow is said to form behind it when it flies through the crystal skies. "

" We just saw a Legendary Pokémon? " Ash asks.

Precosia nods, " Because Ventina is a Sinnoh native I have the Sinnoh dex installed as well, they include Johto, Hoenn, Unova, and Kalos' legendaries. Everyone has heard of Zapdos, Articuno, and Moltres. Sinnoh has Mesprit, Azlef, Uxie, Dialga, Palkia, Giratina, Regirock, Registeel, Regice, Regigigas, Darkrai, Cresselia, Heatran, Shaymin, and Manaphy. Arceus also calls Sinnoh his home when he isn't in the Hall of Legends. "

" Oh, wow, how do you know all that? " Ash asks.

" I grew up on a Berry Farm/Apricorn Farm/Daycare Center so I learned a lot by doing. I also read quite a bit as well. I have books describing the pokémon of every region along with how to care for them, just in case. " Precosia says, her brother Theseus had made sure she knew how to use strategy and tactics, using her guardian's pokémon to give her mock battles that way as well. The trio find a place to rest and Precosia gives Pikachu an Oran Berry, then she lets out the rest of her pokémon. Ash calls out Shedinja and he looks at his new friend.

" What now? "

" Well, Shedinja and Ventina can hunt for their food. We'll have to feed Chalchuuhtlicue, Tethys, and Pikachu. Most of them should be able to forage in Viridian Forest once we reach it. "

Ash nods at this and they get camp set up, Serena making sure to get the fire going and once the food is cooked she offers a portion to the entirety of the Greco-Roman pantheon. Ash blinks and Precosia explains everything to him and loans him one of her books one Greek Mythology that Arceus had gotten spelled so it would switch to whatever language a person was able to read easiest. How he'd done that she didn't know but, she wasn't about to look a gift legend in the mouth especially since he'd saved her life.

She'd even built a shrine to her father on Valencia Island with Theseus' help. Poseidon was becoming well known in the Orange Islands, as was Triton, and her step-mother Amphitrite. She made sure they all got equal praise along with Lady Tethys, Nereus, Pontus, Oceanus…they were all of the sea and deserved equal recognition. She'd work on the water deities first along with the Norse god Loki. She liked him because he was the only one that fought smart in all of Asgard.

Disclaimer: I do not own Percy Jackson and the Olympians or Pokémon.

Precosia:

Ventina- female Wingull

Tethys- female Tentacool

Chalchuuhtlicue- female Magikarp

Ash:

Pikachu- male

Shedinja- male

Author's Note: Ventina is a Sinnoh native, her egg came from Sinnoh to stop any more questions about origin region.