In Fairy Tail fanfiction, the 'Demon Eyes' can be a really cool and mysterious element. They might be a power that a character has, perhaps giving them abilities like seeing through illusions, detecting hidden magic, or even having some sort of mind - control powers over others. It could also be something that is passed down through generations in a certain family or clan within the fan - created story.
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.
In Fairy Tail fanfiction, the Demon Eyes can be portrayed in various ways. They could be a source of both power and danger. Some stories might show that the Demon Eyes give the bearer access to demonic spells and abilities. However, there could also be a cost, like slowly corrupting the character's soul. The appearance of the Demon Eyes could also change depending on the level of power being used, getting more intense and vivid as the character taps into deeper levels of their demonic eye power.
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.
There's a fanfiction called 'Happy and the Lost Treasure'. In this story, Happy teams up with some unlikely allies in search of a legendary treasure. It has a lot of humor as Happy's antics keep the other characters on their toes. The story also has some really cool action scenes where Happy uses his flying skills to outmaneuver enemies.
One idea could be that in their human forms, Happy and Carla are part of a detective agency in Magnolia. Happy is the enthusiastic junior detective while Carla is the more serious and observant one. They solve mysteries related to magic items that have gone missing, often running into other Fairy Tail members who unknowingly hold clues.
In this kind of fanfic, the key elements often involve Happy's new abilities as a dragon. For example, he might have the power to fly faster and breathe different types of magic breaths. Also, the story could explore how Happy copes with this new identity. Does he feel isolated at times? How does he interact with the dragon community if there is one in the fanfic? These are all important aspects.
Another possibility is an accident within the story. Perhaps during a chaotic battle or a magical experiment gone wrong, Happy could be caught in the crossfire or affected by some unforeseen magical consequence. This would be a tragic turn of events for the usually cheerful and helpful Exceed.
One interesting fanfiction could be where Happy and Carla go on a secret adventure without the rest of the guild. They discover a hidden magical place and have to use their unique skills to get back home.
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.