One possible plotline could be that Ash and his Mega Charizard embark on a journey to a new, uncharted region. There, they face a powerful new villain with a team of never - before - seen Pokémon. Along the way, Ash has to train Charizard even further to unlock new Mega Evolutions. They meet new friends who help them in their battles and exploration.
Perhaps the fanfic could be about Ash and Mega Charizard going back in time. They end up in a time when Pokémon and humans had a different relationship. Ash has to use his bond with Charizard to survive in this strange time and also try to find a way back to their own time while making sure not to disrupt the past too much.
One possible fanfiction could be that Ash discovers a new power within Mega Charizard Y during a crucial battle. This power could be a unique type of fire blast that has the ability to heal his Pokémon as well as damage the opponents. The story could revolve around Ash training Mega Charizard Y to master this new power and use it to defeat a powerful villain in the Pokémon world.
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.
In a fanfiction, Ash and his friends are exploring a mysterious new region. They come across a special stone that has the power to trigger mega evolution. Charizard senses the power of the stone and is eager to try it. Ash, with some hesitation, allows Charizard to touch the stone. As Charizard undergoes mega evolution, its appearance changes drastically. It becomes more muscular and its flames burn hotter. With this new power, they are able to face and defeat a group of poachers who were causing trouble in the region.
Well, perhaps there could be a great battle where Charizard's mega evolution is the key to victory. Ash enters a tough Pokémon tournament, and in the final match, his opponent has a really strong Pokémon. Charizard mega evolves and unleashes a super - powerful attack that wins the battle for Ash.
The plot could be that Mega Charizard Y gets injured in a battle. Ash then has to search for a rare healing item in a dangerous, uncharted part of the Pokémon world. He faces many obstacles and other trainers who are also after the item. All the while, Mega Charizard Y is recovering slowly, and Ash is determined to get the item in time to fully heal his beloved Pokémon.
It's possible that he received it as a gift from Professor Oak. Oak might have discovered a way to transfer Mega Stones across regions and sent the Charizardite to Ash in Sinnoh. Another option could be that Ash made a trade with another trainer. He traded one of his Pokémon for the Mega Stone, knowing the potential of Mega Charizard.
Some fanfictions explore the idea of the two Pokemon learning from each other. After the battle, whether it's a win, lose or draw, they might exchange some sort of knowledge or experience. Maybe Greninja learns how to be more aggressive from Charizard X, or Charizard X learns about agility from Greninja. There are also plotlines where the battle is a test of friendship or loyalty between the Pokemon and their trainers.
One possible plotline is that an evil scientist is interested in Charizard's feet for some dark experiment. The trainer has to protect Charizard from being captured. Along the way, they discover that Charizard's feet have a hidden defense mechanism that they can use to fight back. For example, its feet can emit a blinding light. Another plotline could be that Charizard's feet are the only way to access a hidden Pokémon realm. The trainer and Charizard must solve a series of puzzles related to Charizard's feet to open the portal.
In some 'ash takes charizard to kalos fanfiction', the plot could revolve around Charizard getting sick or injured in Kalos due to the new environment. Ash then has to search for a cure or a way to heal Charizard. This could lead him to meet some kind of Pokemon healer in Kalos who teaches him new techniques to take care of Charizard. And during this time, Ash also has to deal with any threats that come their way while Charizard is recovering.
Another theme is growth. Ash may grow as a trainer, learning new strategies to better utilize Mega Charizard's powers. And Charizard might also grow in strength and in its understanding of Ash's commands. For example, they might face a powerful enemy that forces them to adapt and become stronger together.