Well, it's quite possible. Fanfiction writers often come up with the most creative and unexpected crossovers. Since Naruto, Mavis, and Zeref are from different fictional universes, a fanfiction combining them in such a way could be a really interesting read. However, you'll have to do some searching on the various fanfiction hubs to find it. Some of these stories might be quite rare, but if you dig deep enough, you may come across one.
In fanfiction, the idea of Mavis and Zeref having a child often leads to very complex and interesting storylines. Some fanfictions might explore the child's powers, which could be a combination of Mavis's magic and Zeref's unique abilities. For example, the child could have an extraordinary control over life and death magic, or possess some form of enhanced intelligence due to their parents' natures.
It would be a wild mix. Naruto's ninja world combined with the magic of Mavis and Zeref's universe. Maybe Naruto would have some unique magical ninja powers.
The interaction between Mavis and Zeref in fanfiction is significant as it can add new dimensions to the Fairy Tail story. Their relationship can introduce new plotlines and character developments that might not be fully explored in the original series.
In fanfiction, the relationship between Mavis and Zeref can be complex. Some fanfictions might explore their connection in a more romantic light, delving into how their different natures, one being the powerful wizard and the other with his own dark powers, interact. It could be a story of star - crossed lovers, with their fates intertwined due to the overarching plot of Fairy Tail.
One possibility is that the fanfiction focuses on the aftermath of the wedding. How their union changes the world of Fairy Tail. Maybe it brings a new era of peace, as Zeref's power, combined with Mavis' wisdom, could have a positive impact on the magical balance. It could also show their life together, how they support each other, and perhaps start a family of their own, with their children having unique magical abilities.
If they were to work towards a common goal, like saving the Fairy Tail guild from a new and powerful enemy. They would have to rely on each other's strengths. Zeref's dark magic knowledge and Mavis's strategic thinking could complement each other. Through this cooperation, they would see each other in a new light and their relationship would improve.
One idea could be that Zeref and Mavis are somehow trapped in a parallel dimension. In this dimension, they have to work together to find a way out. Along the way, they start to understand each other's pasts and the pain they've both endured. This could lead to a newfound respect between them.
It could be a tragic kiss. Given their complex relationship in the Fairy Tail lore, perhaps the kiss is a final goodbye. Zeref, with his dark nature, might be sacrificing himself or being forced to part from Mavis. And this kiss holds all the unspoken words, all the love that could never be fully realized in a normal way because of their fates.
In a fanfiction, their kiss could be the start of a new era in the Fairy Tail story. It could inspire new magic, new alliances, and new enemies. It might also lead to a journey of self - discovery for both Zeref and Mavis. They could learn more about themselves through this newfound connection, and this could ripple out to affect all the other characters and the overall plot of the Fairy Tail world in many different and complex ways.