Another scenario could be a time - travel gone wrong. Suppose they travel back in time to prevent a great disaster, but in the process, they change the timeline in such a way that their very existence becomes threatened. Their actions could lead to a series of events that result in their deaths, perhaps by causing a powerful ally to turn against them or by creating a new, more powerful enemy.
One possible scenario could be that they sacrifice themselves to save the village from an ultimate evil. They might combine their powers in a final, desperate move that exhausts them completely, leading to their deaths.
Well, in some versions of this fanfiction, it might be that Naruto uses a powerful and forbidden jutsu to defeat an overwhelming foe. This jutsu drains his life force, and Sasuke, who has just realized how much Naruto means to him, catches Naruto as he collapses. It could also be that Naruto is poisoned, and Sasuke tries his best to save him but fails in the end, and Naruto passes away in his arms.
Perhaps in the fanfiction, Naruto is betrayed during the battle. By someone he trusted, like a comrade who was secretly working for the enemy. This betrayal catches him off - guard, and he is severely injured. Unable to fully recover, he succumbs to his wounds during the fight.
One possible scenario could be that Naruto was severely injured in a battle, perhaps against a powerful new enemy. He was brought to the hospital, but his injuries were too grave to be healed, and he passed away surrounded by his friends and family, leaving everyone in deep sorrow.
One scenario might be related to a failed mission. Maybe Naruto is sent on a top - secret mission that is much more dangerous than anyone anticipated. He could be betrayed by someone he trusts during the mission, leading to his death. Or perhaps there are some unforeseen circumstances, like a strange and deadly curse that gets unleashed during the mission which he succumbs to.
Another scenario could be that they are poisoned by a new, undetectable toxin. As they gradually weaken, they try to find a cure but run out of time. Their deaths would be a great loss, and it could lead to major changes in the political and social structure of the ninja world as everyone copes with their passing.
Perhaps in this fanfiction, Naruto is fatally injured by a powerful enemy who has lured him to the Valley of the End. He's outnumbered and despite his best efforts, he succumbs to his wounds. His death then has a profound impact on all his friends and the entire ninja community, leading to a new era of unrest and a search for a new hero.
Perhaps Naruto is betrayed by someone he trusts deeply. This person leads him into a trap at the Valley of the End. Naruto, being caught off - guard, is fatally wounded. His death in this fanfiction could be a tragic end to his journey of becoming a great ninja and a symbol of how even the most powerful can be brought down by treachery.
One possible scenario could be that he's overpowered by a very strong enemy on the bridge. Maybe a new, extremely powerful villain shows up and Naruto, despite his best efforts, just can't hold his own against their unique jutsu or skills.
Another scenario could be that Gohan contracts a deadly and incurable disease in the fanfiction world. Despite the efforts of his family and friends, including the use of any available advanced technology or magic, he succumbs to the illness, leaving everyone in mourning.
One possible scenario could be that Luffy sacrifices himself to save his crew during a major battle against an extremely powerful enemy. He might use all his strength and energy to protect them, and in the end, it's too much for his body to handle.