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.
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.
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.
Perhaps in this fanfic, Naruto's death at the Valley of the End could lead to a new era of power struggles. The other ninja villages might try to take over the Leaf's territory. Meanwhile, Naruto's death could inspire a new generation of ninjas who want to uphold his ideals. They would have to fight against the odds to keep the peace that Naruto once fought for.
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.
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 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.
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.
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.
Madara Uchiha might be the main antagonist. He has grand plans for the ninja world. He could see Naruto as a threat to his vision and engineer a situation in the Valley of the End where Naruto is killed, either directly or by using Sasuke as a pawn.
One possible scenario could be that he succumbs to the hardships in the village as a child. Maybe the villagers' hatred towards him is too much to bear, and he gets into a situation where he can't defend himself. Another could be that he's on a mission early on and it goes horribly wrong, perhaps facing an enemy far too powerful for his young self.