In some 'rwby neo dies fanfiction', Neo might die due to the consequences of her own actions. She could have made a deal with a dark force in order to gain power, but in the end, the power overwhelms her and she succumbs to it, taking her life.
In some scenarios, she might die heroically in a battle against a powerful Grimm. For example, she could sacrifice herself to save her friends from a horde of Nevermores. Another possibility is that she succumbs to an unexpected betrayal within the story, perhaps by a character who was thought to be an ally. Or she could die due to some unforeseen magical or technological accident in the RWBY universe.
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.
For Blake and Yang, Neo's death could be a reminder of the harsh reality of their world. They might become more cautious and protective of their team. They could also start to question their own beliefs about redemption and whether every enemy can be saved or not.
One possible scenario could be that Tony is in Siberia on a mission gone wrong. Maybe he's facing a powerful enemy there, and despite his best efforts, he gets fatally injured in a fight. Another could be that the harsh Siberian environment plays a role, like he gets caught in a blizzard and succumbs to the extreme cold.
One possible scenario could be that Percy sacrifices himself to save Annabeth from a powerful and deadly monster. Maybe a huge and ancient sea creature that only Percy can hold off long enough for Annabeth to escape, but at the cost of his own life.
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 Tony sacrifices himself to save a teammate during a dangerous mission. Maybe he takes on a bomb - defusing task and runs out of time, dying heroically.
One possible scenario could be that Percy is overpowered by the various monsters in Tartarus. Maybe the sheer number of foes like the giants or the more terrifying creatures there are too much for him to handle, leading to his death.
One possible scenario could be that Edward sacrifices himself to save Bella from a powerful new vampire threat. Another might be that he succumbs to an illness that vampires in this fanfic world are suddenly vulnerable to. Or perhaps he is killed in a battle against a group of werewolves gone rogue.
Another scenario could be that Iron Man is poisoned or infected with a deadly alien virus. He tries to fight it off but eventually succumbs to it. His friends in the Avengers try their best to save him but are unable to. This would be a really tragic way for him to go, especially considering how much he has done for the team and the world.