Ash might become more conflicted. He has always been on the side of good, but with Giovanni as his father, he'd have to grapple with his family ties. He could become more secretive and brooding as he tries to figure out how to balance his own values with this newfound family connection.
Ash could also develop better leadership skills. As an assistant, he might have to lead small teams during research expeditions. He would need to make decisions quickly and fairly, considering the safety and goals of the team. This would be a big change from his usual role as a solo trainer, and it would shape him into a more well - rounded character in the fanfiction.
Dark Ash is more ruthless compared to the original Ash. While the original Ash is kind - hearted and values friendship, Dark Ash may use his Pokemon just as tools for power. He doesn't care about the feelings of his Pokemon as much as the regular Ash does. For example, he might overtrain them without considering their well - being.
Ash's character would likely become more confident. Starting with a Charizard, which is a very powerful Pokémon, would give him an edge in battles. He would also become more patient as Charizard can be difficult to train at times. For example, when Charizard refuses to listen, Ash would have to find new ways to communicate and gain its respect.
Ash would likely become more responsible. Since Dratini is a relatively rare and potentially powerful Pokémon, he'd have to take extra care. This could make him think more before acting in battles and other situations.
Ash often becomes more confident in these fanfictions. He learns new ways to communicate with his Pokemon during contests, which makes him a better trainer.
Charizard could be a bit more indifferent. It's a proud and strong Pokémon. It might just snort when it sees Ash in a dress, as if to say 'This is a strange human thing, but it doesn't affect our relationship'. However, if other Pokémon made fun of Ash because of the dress, Charizard might get protective.
Maybe Team Rocket could have a new member who is a ninja. This new member could be Ash's main rival. They would try to steal Ash's pokemon in more sneaky and ninja - like ways. And Ash would have to use his ninja skills to protect his pokemon and defeat this new rival from Team Rocket.
Ash may become more confident. Capturing Mewtwo is no easy feat, and if he manages it, it would boost his self - assurance. He might also become more empathetic as Mewtwo has a complex personality. Understanding Mewtwo could make Ash better at relating to other Pokémon with similar issues.
His physical abilities change too. He might be stronger and faster as a werewolf. This could lead to a change in his confidence level. He might be more bold in battles, but also more cautious as he doesn't want to fully expose his werewolf side. He has to find a balance between using his new powers and still being the Ash his friends know and love.