For Natsu, it would be devastating. Happy has been his constant companion since they were young. Natsu would likely be filled with rage and grief, which could potentially lead him to seek revenge against whoever or whatever caused Happy's death.
The entire Fairy Tail guild would be in mourning. Happy was a beloved member, always there to bring a smile or some comic relief. His death would create a somber atmosphere in the guild, and it could also serve as a unifying factor, making the members more determined to protect each other and prevent further losses.
The people closest to Naruto, like Hinata, would be completely devastated. She would be by his side, crying and feeling like her world is falling apart. The thought of losing Naruto, the man she loves, would be almost too much to bear.
For one, it would create a great deal of grief among the other characters in the fanfiction. His friends like Sasuke, Sakura, and Kakashi would be devastated. The readers would feel their pain. It also stirs up emotions like admiration for Naruto's courage. He's giving up his life to stop a great evil, which is a very noble act. And there might be a sense of anger too, towards the situation that led to his death.
One of the funniest scenarios could be when Happy tries to 'help' Natsu cook but just ends up making a huge mess. He might accidentally add too much of an ingredient or knock over pots while flying around the kitchen in excitement.
It objectifies the character. By focusing on such inappropriate aspects, it reduces the character to a mere object of sexual fantasy rather than a well - developed character in the story.
One idea could be that Happy's death shatters the Fairy Tail guild. Natsu, being his closest friend, goes into a deep depression. The guild loses its usual cheer and the members struggle to come to terms with the loss. They might hold a grand memorial for Happy, and throughout the fanfiction, it could show how each character copes in their own way, like Lucy writing in her diary about all the memories she had with Happy.
Well, it's the connection to the original Fairy Tail world. We already care about the characters, and when fanfiction adds an emotional layer, it makes us feel even more deeply for them. For example, when a fanfic shows a character's struggle with loneliness, it hits hard because we know the character from the original series.
Firstly, it promotes an inappropriate view of sex. Fairy Tail is originally a work about friendship and magic, adding erotic elements distorts its essence. Secondly, it is not suitable for a wide audience, especially children and teenagers who might be exposed to it accidentally.
In some fanfiction, a human who is an artist finds a fairy tail. The fairy in the tail has the power to bring art to life. The human and the fairy work together to create a beautiful, magical art gallery. They invite other humans and fairies to see their creations, spreading happiness and harmony between the two worlds.
Some fanfictions also feature Happy and Charle teaming up to solve a mystery within the Fairy Tail guild. For example, they could be investigating strange disappearances of guild members. They use their unique abilities, Happy's flight and Charle's foresight, to piece together the clues and get to the bottom of the mystery.
One interesting idea could be exploring Happy's final moments in a very emotional way. Maybe it shows his selfless acts even in the face of death.