Bardock's Adventures of Pokémon Heroes

Bardock's Adventures of Pokémon Heroes is an upcoming origin story crossover to be created by Hiatt Grey.

Plot
The film is set in the Venetian-esque city of Alto Mare, protected by the dragon siblings Latias and Latios. Their father, also a Latios, is said to have saved the city from an evil Pokémon Trainer and their Kabutops and Aerodactyl whilst transforming the city's streets into canals. The citizens built the Defence Mechanism of Alto Mare (or “D.M.A.” for short) to protect the city if necessary, but have never had to use it. The father Latios died, leaving behind the Soul Dew, said to contain his own soul and can power the D.M.A.

In the present day, Team Rocket agents Annie and Oakley acquire a book detailing the history of Alto Mare, plotting to control the D.M.A. Ash, Misty, and Brock are touring by and see an invisible Latias. Annie and Oakley stalk Latias, who disguises herself as a human girl, trying to capture her using their Espeon and Ariados. Ash and Pikachu come to the rescue, guiding Latias to safety but she vanishes when Ash’s back is turned.

Visiting the museum, the trio meet the curator Lorenzo who details Alto Mare’s history, the D.M.A., and the fossilized Pokémon on display. Ash spots a girl, Bianca, who resembles Latias’ disguise, and chases her across the city, but she does not recognise him. Latias herself appears, guiding Ash and Pikachu to a hidden garden where she and Latios live, protected by Lorenzo and Bianca, his granddaughter. While Pikachu plays with Latias and Latios, Lorenzo shows Ash the Soul Dew, unaware that Annie and Oakley’s drone has infiltrated the sanctuary.

That night, Annie and Oakley sneak into the garden, successfully capturing Latios and the Soul Dew, but Latias escapes. Bianca and Lorenzo attempt to stop the thieves from using the D.M.A. but are captured, the Soul Dew and Latios are used to power the machine. Latias goes to Ash for help, with Latios’ “Sight Sharing” ability allowing them to witness the events in the museum. Oakley becomes power hungry, using the D.M.A. to resurrect Kabutops and Aerodactyl, and initiates a citywide lockdown to prevent interference. Ash, Pikachu and Latias evade the lockdown, racing to the museum while being pursued by the fossilised Pokémon.

Oakley tries to drown Ash, Pikachu and Latias, but the latter’s psychic powers cause the D.M.A. to go out of control. Reaching the museum, the trio rescue Latios and shut down the machine. However, Annie tries to take the blackened Soul Dew, which shatters, causing all of the city’s water to flow out and return as a tidal wave. Latias and Latios combine their powers to stop the wave, Latios giving his life in the process. Kabutops and Aerodactyl perish again, while Annie and Oakley remain trapped in the D.M.A..

Ash and friends find Latias, realising Latios has died, but they share one last vision as he passes away. Several days later, Ash, Misty and Brock get ready to leave Alto Mare, saying goodbye to Lorenzo, but Bianca does not appear. On their way out of the city, they spot Bianca on the docks but she isn't wearing her hat (the usual difference between Bianca and Latias). The girl gives Ash a sketch of him and Pikachu, kisses him on the cheek, and leaves without saying a word. Whether the girl was Bianca or Latias is left to the viewer.

But later, Latias then finds Bardock who was on his way to Japan for a job, but Bardock still remembers Latios. When then suddenly, Latias presents the Soul Dew and she uses her powers and brings back Latios! And then suddenly, they gain ability to speak! And they have decided to join with Bardock and they head off for Japan.

Trivia

 * This film shows how Bardock befriended Latios & Latias, and is a prequel to Brian and the Eeveelution Family's Adventures Series.