In the fanfic, perhaps Ash releases Charizard due to some kind of misunderstanding. Maybe there was an incident where Charizard's power accidentally caused harm, and Ash, thinking it's the best for everyone, releases it. However, as the story progresses, Ash discovers the truth and has to go on a journey to find Charizard and bring it back.
One possible plot could be that Ash realizes Charizard has grown too powerful for the current region he's in and decides to release it so it can find a more challenging environment. Maybe it goes off to a far - off mountain range where it battles and befriends other powerful Pokémon.
The plot could be that Ash is in Kalos to participate in a special Pokémon tournament. Misty hears about it and decides to come support him. Charizard, of course, is Ash's main battling Pokémon. Along the way, they meet a new type of Pokémon that is causing trouble in the region. They have to figure out a way to stop it, with Charizard using its powerful attacks. And in the end, Ash wins the tournament with the help of Misty and Charizard.
It could be about Ash and his Charizard training to master the blue flames. Maybe they encounter a powerful enemy that can only be defeated with this new, more powerful form of Charizard's flames.
Well, first of all, the reason for the release is a key element. It could be due to Charizard's own desire for freedom or Ash thinking it's best for Charizard's growth. Then there's the impact on Ash's journey. His journey might take a different turn without Charizard by his side. The fanfictions also often explore the memories Ash and Charizard shared. These memories can be bittersweet and add depth to the story. Additionally, the possibility of a reunion is another element that keeps readers interested.
It could make Ash more self - reflective. Releasing Charizard, a Pokémon he's so close to, would force him to think about his role as a trainer. He might become more cautious in future decisions about his Pokémon.
Maybe in the fanfic, Ash and his friends are exploring an ancient ruin. Charizard, being curious, wanders off and accidentally triggers a booby - trap. It gets severely injured. Ash is then on a race against time. He needs to find a way to heal Charizard before it's too late. Along the way, he meets a mysterious old trainer who gives him some advice on a rare and powerful healing method. But the method requires Ash to face his own inner demons and prove his worth as a trainer.
Well, it could mean that Ash has an extremely powerful ally in the Sinnoh region. Maybe he uses Mega Charizard to battle against powerful gym leaders or face off against the evil teams more effectively. It might also attract the attention of other trainers who are either in awe or jealous of his powerful Pokémon.
The plot might involve Ash starting his journey all over again, but this time with a Charizard as his very first Pokémon. Since Charizard is a powerful and somewhat stubborn Pokémon, Ash would have to learn how to handle it right from the start. He could face challenges like other trainers trying to steal Charizard because of its rarity. Ash would have to prove his worth as a trainer and his connection with Charizard to keep it by his side.
The plot could be that Ash is orphaned at a young age and Charizard finds him. Charizard then decides to raise Ash in the wild. Ash grows up learning survival skills from Charizard and how to communicate with other Pokémon directly.
The plot could be that Ash enters a Kalos - only Pokémon competition with Charizard. They face strong opponents with unique Kalos Pokémon. Charizard might learn new moves by observing the local Pokémon. For example, it could see a Delphox use a powerful fire - type move and try to adapt it to its own style.
The plot might revolve around Ash leaving Charizard because he believes Charizard has a greater purpose elsewhere. For example, there could be a group of wild Charizard in need of a leader, and Ash realizes that his Charizard is the one. So he leaves it to fulfill that role. In the fanfiction, we could see Charizard initially being reluctant but then gradually accepting its new destiny and leading the group in a new and better way.