Since Gray is often seen as a bit of a lone wolf and Juvia is very determined in her affections, the child could be independent yet very loyal. It would be the type to pursue its own goals but would also stand by its friends and family no matter what. For example, in a battle, it would fight bravely on its own but also make sure to protect those it cares about. And in daily life, it would be okay with doing things alone like Gray, but also have Juvia's eagerness to be around loved ones when possible.
Well, their child might inherit Gray's ice - making magic. Since Gray has such strong control over ice, it could be passed down. And maybe also get some of Juvia's water magic, which could combine in interesting ways. For example, the child could create ice sculptures that are constantly being reshaped by flowing water - like magic.
In many fanfictions where Gray confesses to Juvia, it's often a very emotional moment. It might happen after a big battle where they realize how much they mean to each other. Gray could finally admit his feelings that he has been suppressing for a long time. Maybe he sees Juvia in danger and that makes him realize he can't hide his love anymore.
Gray would be devastated. He might go into a state of deep depression, isolating himself from the rest of the Fairy Tail guild. He would blame himself for not being able to protect her, especially if her death was related to her love for him. Gray would probably be filled with anger as well, and he would vow to take revenge on whoever was responsible for her death.
In fanfiction, Gray's love for Juvia can be portrayed in many ways. Sometimes it's a slow - burn kind of love. Gray, who is initially cold towards Juvia, gradually realizes her importance in his life as she is always there for him, through battles and difficult times.
Well, it could make Gray feel an extreme sense of guilt. He might blame himself for not being able to protect her. And this could lead to him becoming more withdrawn and brooding, perhaps even pushing away his friends as he grapples with the loss.
Their friends in Fairy Tail would likely be very excited. Erza, for example, would probably be super supportive and offer practical advice on things like baby - proofing a home. Natsu might be a bit clueless at first but would be really happy for them. Lucy would be thrilled and might start knitting baby clothes. Happy would be flying around them, chirping happily. Overall, their friends would form a great support system for Gray and Juvia during this time.
Well, in some fanfictions, Gray's love for Juvia is shown through his jealousy. When other guys get too close to Juvia, Gray gets this possessive feeling that he doesn't quite understand at first. It's a sign that his feelings for her are deeper than he thought.
In fanfiction, a child of Natsu and Erza might inherit Natsu's fiery temper and love for adventure. They could also have Erza's strong sense of justice and discipline. Maybe they'd have Natsu's pink hair and Erza's beautiful eyes. And they'd probably be a powerful mage, combining Natsu's dragon slayer magic with Erza's requip magic.
Natsu is hot - tempered. This could be both good and bad for the adopted child. On one hand, it would teach the child to be assertive. On the other hand, the child might also pick up some of Natsu's impulsive behavior. But overall, Natsu's loyalty and big heart would make the child feel loved and protected.
Another great author is 'RainbowMageFan'. This author likes to create unique and exciting plotlines. For example, they might write a story where Juvia and Gray get transported to a magical realm full of strange creatures and they have to find their way back while also dealing with their growing feelings for each other. Their writing style is very engaging.