This is my initial story idea, its still unrefined but hopefully it tells a bit about the characters, and what they might look like.
Many years ago God Poseidon had in possession a mysterious and powerful object that could change the world by turning the land of entire planet to sea. Before Poseidon got to use it and take over the world the artefact got stolen by cunning pirates, who risked their life to protect the human race.
One night a young boy gets awaken by a loud noise in his house, when he gets to the source of the noise in the cellar he discovers a very old chest with a broken lock. Inside the chest he finds a letter that turns out to be written by boy's great grandfather. The letter was detailing what was kept in the chest and how important it is to protect it. After realising how powerful the relic was he decides to go onto a sea adventure to get back the object. Luckily for the boy his great grandfather, left him a magical crystal ball, which holds one in a kind mythic creature, that is going to become boy's companion, and friend.
Hero- A young boy about age 16, who's great grandfather was a pirate and stole an object that belonged to the god of the sea. The boy has a weakness of not being able to swim which makes him worried that he wont be able to stand up to the task of stealing from the Poseidon.
Side Kick- A mythical creature enclosed in a magic crystal ball. The creature has two incarnations one is of a sea horse inside the ball, and the second of a full size mythical half horse half fish monster, the seahorse will only transform when the boy is in serious trouble.
Villain- God of the Sea, Poseidon who wants to rule the world by turning all of the land into water...