The Akatsuki would surely be affected. They would lose one of their members, which could disrupt their plans. Also, it might change the way other characters view Naruto. Some might see him as a more formidable threat, while others might see him as a hero for taking out a dangerous enemy.
Well, it could happen if Naruto has some sort of special weapon. For example, he might get a sword that can disrupt Hidan's connection with his voodoo - like powers. Once that connection is broken, Naruto could easily defeat and kill Hidan. Also, Naruto's growth in chakra control and strength could play a role. With his enhanced abilities, he could overpower Hidan and deliver a fatal blow.
A possible main character could be an OC who is a young and inexperienced shinobi. This shinobi accidentally stumbles upon Hidan's secret sacrificial site. Hidan, seeing this as an opportunity sent by Jashin, decides to make the shinobi his sacrifice. The young shinobi then has to quickly grow and learn to use their latent ninja skills to survive the encounter with Hidan and potentially expose his actions to the ninja world.
The main characters are Kinji Tooyama and Aria H. Kanzaki. Kinji has a special ability that gets activated under stress. Aria is a strong and determined girl.
It's a complex situation. Different storylines and villains have targeted the Avengers, but no one specific character can be said to have killed them all outright.
Kang's demise in comics is a complex matter. It could be a result of a team-up of heroes, or it might be due to an unexpected turn of events involving multiple characters and their actions.