Well, a story could involve Tails being caught in a trap set by an evil villain. This villain could be someone who has a grudge against Sonic and decides to target Tails as a way to get to Sonic. Tails, despite his best efforts to escape, is unable to do so. As he is held captive, he refuses to give in to the villain's demands, which enrages the villain and leads to his untimely death. Another idea is that Tails discovers a dark secret about his past or his family that causes him so much emotional turmoil that he makes a rash decision that ultimately costs him his life. It could be something like finding out that his family was involved in something bad in the past and he feels the need to make amends in a dangerous way.
One possible storyline could be that Tails gets involved in a dangerous adventure where he sacrifices himself to save his friends. For example, he might be facing a powerful new enemy that has invaded Sonic's world. Tails, being the intelligent and brave fox he is, uses his mechanical skills to create a diversion that allows Sonic and the others to escape, but in the process, he is fatally injured. Another storyline could be related to a disease outbreak in his world. Tails tries to find a cure but ends up being infected himself. As he weakens, he uses his last moments to pass on his research to the other characters so they can continue the fight. A third storyline could be a time - travel gone wrong. Tails might be sent to a different era where the conditions are too harsh for him to survive, and his death in that era has a profound impact on the future when Sonic and the gang discover what happened.
One possible storyline could be that Danny sacrifices himself to save the world from a powerful and evil ghost. Maybe he uses all his energy in a final battle and fades away, leaving his friends and family to mourn. Another could be that he's tricked by a villain into a death - trap that he can't escape from.
Perhaps in the fanfiction, Emily has a secret that she's been hiding. Her death could be related to this secret being exposed. For instance, if she was involved with a group that was against the Miraculous holders in some way, and when the truth comes out, it leads to her demise, either by the hands of the heroes or the villains she was associated with.
In a more complex story, there could be a curse placed on Pikachu by an ancient Pokemon spirit. This curse gradually weakens Pikachu over time. As it gets sicker, Ash tries everything he can to find a cure. But in the end, Pikachu's body gives out. Ash is left to deal with the grief, and he embarks on a journey to find a way to break the curse and bring Pikachu back.
A common scenario in such fanfictions is that Hinata sacrifices herself in a war - torn situation. For instance, in a great ninja war, Naruto is the key to victory but is targeted by the enemy's most powerful forces. Hinata, with her unwavering love for Naruto, jumps in front of a massive attack aimed at Naruto, knowing full well that it will cost her life. This selfless act then serves as a major turning point in the story, inspiring Naruto and his comrades to fight even harder.
One possible storyline could be that as Peter Pan dies, Tinker Bell uses all her magic in a desperate attempt to save him. She might make a deal with the Neverland's dark forces, sacrificing her own well - being for his life.
One possible storyline could be that Peter Parker sacrifices himself to save the city from a powerful new villain. Maybe he uses all his strength and resources to stop a doomsday device, but at the cost of his own life. The city then mourns their fallen hero, and his friends and family are left to pick up the pieces. His death could also inspire a new generation of heroes.
Perhaps Finn's death is an accident. He could be exploring an uncharted area of Ooo and stumble upon a dangerous trap or ancient magic that he doesn't understand. His death shocks everyone in Ooo, and his friends start to question the safety of their continued adventures. This could lead to a whole new set of adventures for his friends as they try to come to terms with his death and make Ooo a safer place in his memory.
One possible storyline could be that she sacrifices herself to save her family or friends. Maybe in a battle against dark wizards, she uses a powerful spell to hold off the enemy long enough for others to escape, but it drains her life force. Another could be that she succumbs to a mysterious and incurable magical illness that has been plaguing the wizarding world. This would lead to a very sad and poignant story as her loved ones struggle to come to terms with her impending death.
One possible storyline could be that in a battle against a powerful dark wizard, Harry sacrifices himself to save Hermione from a fatal curse. Another could be that he gives up his life to protect Hermione from a dangerous magical artifact that is about to explode. Or perhaps he takes on a deadly disease that was meant for Hermione, knowing it would cost him his life.
Well, one way to make it emotional is to have a slow - build - up to Tails' death. Start with him being full of life and having big dreams. Then, as the danger approaches, show his fear and determination. You can also add flashbacks of his happiest moments with his friends. For instance, when he first met Sonic or when they had a big victory together. When he finally dies, have his friends find something that was very precious to him, like a handmade gift for Sonic. This would really tug at the heartstrings. Additionally, you could have a scene where Tails says goodbye to each of his friends individually, with heartfelt words that show how much he cares about them.