The Akatsuki members are the main characters. They bring their own unique abilities and goals. For example, Hidan's immortality could play an interesting role in the Pokemon world. He might be more reckless in battles because he knows he can't die easily. Kisame, with his shark - like appearance, could have an affinity for Water - type Pokemon and be really strong in underwater Pokemon battles. These characters' interactions with the Pokemon and each other are what drive the story in an Akatsuki Pokemon Fanfic.
Sakura Akatsuki is likely one of the main characters. She is probably the central figure around which the story revolves. And Lemon might be either another important character, perhaps a friend, a magical being, or an object of significance in the fanfic.
There could be a fanfic where the Akatsuki is on a mission in the Pokemon world to capture a powerful and legendary Pokemon. They would have to face off against other trainers and Gym Leaders. In this story, Itachi might use his intelligence to outwit his opponents in Pokemon battles, similar to how he outmaneuvered his enemies in the Naruto series.
The main characters could be the leaders of the Akatsuki group at the high school. They would be the ones making the big decisions and leading the group in various school - related activities. For example, they might be the captains of different school clubs that the Akatsuki group is involved in.
Deidara is also a popular character to feature. His explosive personality can be played up for comedic effect. He could be constantly getting into trouble because of his short temper, but in a really funny way, like accidentally blowing up his own art supplies instead of his intended targets.
Sakura for sure. And then it might be Deidara. His love for art and his explosive personality would be really funny when paired with Sakura. Also, Sasori could be in it. His puppet - like self and Sakura's medical knowledge could lead to some really strange and humorous interactions. For example, Sakura might mistake Sasori's puppet parts for real injuries and try to 'heal' them.
Kakuzu could also be a main character in some 'akatsuki hinata fanfic'. His money - loving nature can be a source of conflict or comedy when Hinata, with her selfless values, is around. He might be constantly annoyed by her giving nature.
In 'akatsuki watches death battle fanfic', the Akatsuki members themselves would likely be the main characters in the sense that they are the ones observing. It could be Itachi, with his calm and calculating nature, who might be making astute observations about the fanfic's battles.
It could also be a new character created specifically for the fanfic. A young girl who has a natural gift for music and can communicate with Pokemon through melodies. She might use her talent to solve problems in the Pokemon world, like helping Pokemon that have lost their way or are in distress because of some dark force that is disrupting the natural harmony of the Pokemon world.
I'm not sure exactly as it depends on the specific 'the challenger pokemon fanfic'. But usually, there would be a young and ambitious Pokemon trainer as the main character. This trainer would be eager to prove themselves in the Pokemon world.
There might also be a villain who wants to use the power of fennel - influenced Pokemon for their own gain. This character would add conflict to the story and be a major antagonist for the other main characters to face.