Obviously, Ash and Butterfree are the main characters. Ash is the trainer and Butterfree is his Pokémon that returns.
The main characters are Ash and Butterfree. However, depending on how the fanfiction is written, there could be other supporting characters. Maybe some of Ash's friends like Misty or Brock could be involved, if the story is set in a context where they are around. Or perhaps there could be new characters that are introduced because of Butterfree's return, like a trainer who has a connection to Butterfree's time away from Ash.
It could be about Ash's Butterfree coming back in some way. Maybe it returns to Ash after a long time apart. It might show their reunion, and how they interact again, like Butterfree showing its affection for Ash once more.
The main characters in 'ash returns home with greninja fanfiction' are Ash and Greninja. Ash, the Pokémon trainer, has journeyed far and wide with Greninja by his side. Greninja is not just a Pokémon to Ash but also a friend and a powerful ally. They have shared many experiences together, and their relationship is at the core of this fanfiction.
Obviously, Ash would be one of the main characters. His Pikachu would also be there as his constant companion. Serena might also be a main character as she has a connection to Ash and is from Kalos.
One possible fanfiction could be about Ash and Serena going on an adventure specifically to find a rare pink Butterfree. Maybe they hear rumors of a special meadow where these pink Butterfree are sighted. Along the way, they face challenges like wild Pokémon and difficult terrains. Ash's determination and Serena's strategic thinking help them get closer to their goal. When they finally find the pink Butterfree, it's a magical moment, and they learn some valuable lessons about friendship and the beauty of nature.
His best friend from before the war could be a main character. This friend might have been waiting for Ash's return and now has to deal with the changed Ash.
Obviously, Ash is the most important character as the story revolves around his death and return. Pikachu is also crucial as his closest pokemon companion. His friends like Misty, Brock, and Serena would play significant roles as they would be affected by his death and overjoyed at his return.
Obviously, Ash would be the main character. Then there could be female characters who form his harem. Maybe some of his long - time friends like Misty and Brock could also be involved in some way, even if they are not part of the harem directly. There might also be new characters that he meets during his disappearance.
It could be that the pink Butterfree is actually a transformed Pokémon. In the fanfiction, it could be a Pokémon that was experimented on by an evil scientist and turned into this pink Butterfree. Ash and Serena have to figure out how to turn it back to its original form. Along the way, they discover the scientist's lair and have to battle his other creations. This would be an exciting adventure full of mystery and action.
Obviously, Ash and Jolteon are the main characters. Ash is the trainer, and Jolteon is his Pokémon. But there could also be other characters from the Pokémon universe that might be involved, like Ash's friends or other trainers he meets along the way.
Obviously, Kushina is one of the main characters. Naruto is also a central figure as her son. Since it's related to the Naruto universe, characters like Sasuke, Sakura, Kakashi might also be important in the fanfiction. They could interact with Kushina in various ways, like Sasuke might be skeptical of her at first, or Sakura could be eager to learn from her.