A storyline could involve Ash's Pokemon getting seriously ill or injured in a way that he can't immediately fix. He would feel helpless and guilty, especially if he thought it was his fault for leading them into a dangerous situation. This would cause him to be withdrawn and depressed. He might stop training and traveling for a while as he focuses all his energy on trying to heal his Pokemon.
One possible storyline could be that Ash loses a really important Pokemon battle, like a championship match. This loss makes him question his skills as a trainer. He might start to isolate himself from his friends, like Pikachu and Brock. Another could be that a long - lost friend or Pokemon from his past suddenly reappears in a difficult situation, and Ash blames himself for not being there before. This could lead to his depression.
Perhaps the story could involve a mystery related to Serena's pregnancy. There could be some strange events or prophecies in the Pokémon world that seem to be connected to the baby. Ash and Serena then have to go on a journey to figure out what it all means. Along the way, they meet new Pokémon and characters who either help or hinder their search for the truth.
One possible storyline could be that Alexa is researching a rare Pokemon in a region. Ash arrives in the same region on his journey. Their paths cross and they end up in a friendly competition to see who can find and catch the rare Pokemon first. Along the way, they have battles with other trainers and help each other out in tough situations.
Maybe Ash's old Pokémon have unique skills that are rare in Kalos. So, he uses them to gain an advantage in Pokémon contests or battles. His Charizard, for instance, could be a formidable opponent against Kalos's dragon - type Pokémon, and this could lead to some exciting rivalries and plot twists.
One possible storyline could be that Ash is a knight in training and Serena is a noble lady. Ash has to prove his worth in a jousting tournament to win Serena's hand in marriage. Another could be that they are both on a quest to find a magical Pokemon that is said to have the power to save the medieval kingdom from an evil sorcerer. And a third could be that Serena is a healer and Ash is a warrior, and they team up to fight off a horde of dark - type Pokemon that are attacking the villages.
One possible storyline could be Serena feeling heartbroken and then deciding to focus on her own Pokemon journey independently. She might strive to become a better Pokemon trainer on her own terms, proving herself not just for Ash but for her own self - worth.
Perhaps Leaf betrays Ash because she becomes jealous of his friendship with Pikachu. She might feel like Pikachu gets all of Ash's attention and decides to side with a group that wants to separate them. This could lead to Ash having to fight not only to save Pikachu but also to win Leaf back.
One possible storyline could be that Saturn and Mars are on a secret mission to find a rare and powerful Pokemon that could change the balance of power in their organization. They face many challenges along the way, like rival teams trying to stop them.
One interesting storyline could be Ash befriending Mewtwo in a more in - depth way. Maybe Ash helps Mewtwo understand the true meaning of friendship among humans and Pokemon. He could show Mewtwo that not all humans are bad by introducing him to his friends like Brock and Misty, and how they all care for their Pokemon.
One possible storyline could be that a rival team kidnaps Lillie to use her knowledge of the Aether Foundation for their own evil plans. Another could be that a powerful and mysterious Pokemon trainer, jealous of Lillie's bond with certain Pokemon, takes her. Or perhaps an ancient and long - forgotten evil entity returns and targets Lillie for reasons related to her unique connection to the Pokemon world.
One possible storyline could be that Meowth is abandoned by a trainer who has caught a stronger Pokemon and no longer has use for him. Meowth then has to fend for himself on the streets, facing other wild Pokemon and trying to find food. He might also start to question his self - worth after being discarded so easily.