In such a fanfiction, one possible scenario could be that Gladion gets involved in a battle against a powerful and malicious Pokemon trainer. The trainer's Pokemon might use a super - powerful attack that Gladion's Pokemon can't withstand, and in an attempt to protect his Pokemon, Gladion gets caught in the crossfire and is killed. Another scenario could be that he stumbles upon a dangerous, secret organization within the Pokemon world that doesn't want their secrets exposed. They might target Gladion and assassinate him to keep him silent.
Well, it could be that Gladion is trying to stop a powerful, dark - type Pokemon from causing chaos. This Pokemon has some unique and deadly abilities. During the fight, Gladion misjudges the Pokemon's next move. The Pokemon uses a move that creates a dangerous environment, like a field of sharp spikes or a collapsing cave. Gladion is unable to escape in time and gets killed. Or, in the fanfiction, there could be a curse or an ancient power that targets Gladion because he has a certain item or knowledge that the force doesn't want to be in the hands of the living.
It could be a power - hungry Pokemon trainer. This trainer might see Gladion as a threat to their goal of dominating the Pokemon league or the entire Pokemon world. So, they plan and execute his killing.
One possible scenario could be that he is killed in a lightsaber duel by a powerful Sith opponent. Maybe this new Sith has some secret technique that Anakin couldn't counter.
One possible scenario could be that Natsu is killed in a battle against a powerful and unexpected enemy. Maybe a new dark mage appears with powers that can overpower Natsu's fire magic.
One possible scenario could be a power imbalance. Maybe Sasuke discovers some new, extremely powerful jutsu that Naruto has no defense against. For example, a jutsu that can nullify Naruto's chakra or attack his spirit directly. Another possibility is a miscommunication or a breakdown in their relationship. If Sasuke believes Naruto has betrayed him in some way, his anger could lead him to kill Naruto. However, this goes against the core of their bond in the original series.
Maybe in the fanfiction, Gladion is from a noble family in the Pokemon world. His family has certain expectations for his wedding. He, however, chooses to marry someone who is not from a noble background. There could be a lot of drama with his family trying to stop the wedding at first. But in the end, they see how much he loves his partner and give their blessing.
Well, in a fanfiction, he might be killed by his own hubris. Let's say he continuously underestimates the power of human ingenuity. A group of scientists manage to create a device that disrupts his energy source. While he's weakened, the military launches a full - scale attack using advanced weaponry specifically designed to target his unique physiology. So, his overconfidence in his invincibility leads to his downfall.
One scenario could be that Wendy's Pokemon was stolen by a villain. This would be a very distressing situation for her as she would be worried about the safety and well - being of her Pokemon.
One possible scenario could be that the Dursleys, out of their long - held hatred and jealousy, manage to poison Harry's food. In the fanfiction world, they might find a way to obtain a powerful and undetectable poison. Another could be that they stage an 'accident' like a fire in his room while he's asleep. They could block his escape routes and let the fire consume him.
One possible motive could be revenge. Another character might have a grudge against Lucy for something she did in the fictional world, like betraying a group or stealing something precious.
In some 'goku gets hurt fanfiction', he might get hurt while protecting his friends or family. For example, he could take a fatal blow meant for someone else. This would not only physically harm him but also add an emotional aspect to the story as his loved ones would be worried and try to save him.