Maybe Mavis, in her exploration of different realms, ends up in the ninja world. She gets into trouble and Naruto comes to her rescue. Naruto is intrigued by her magic and Mavis is impressed by his ninja skills. This encounter plants the seed for their relationship that eventually leads to marriage.
Naruto has shown incredible feats of strength, speed, and endurance. He has defeated some of the most powerful villains in his universe. But Mavis is no slouch either. Her Fairy Law is a very powerful spell. If we consider their growth potential, Naruto has the ability to constantly get stronger by unlocking new forms of his power, like Sage Mode and later the forms related to the tailed beasts. Mavis, on the other hand, has a deep knowledge of magic that could potentially allow her to counter any of Naruto's attacks. It really depends on the situation, the location, and how well they know each other's abilities.
One of the main characters could be Wayne, the werewolf. He and his family could bring some fun and chaos to the story. Maybe they come to visit Johnny and Mavis, and the werewolf pups accidentally cause some trouble in the baby - proofing of the house. Also, Griffin, the invisible man, could be there. He could use his invisibility to play pranks on the couple during their pregnancy, but also be a good friend when they need help.
Their relationship would likely become more centered around the baby. They would have less time for just themselves and more time taking care of the baby's needs.
One idea could be that in the fanfiction, Mavis discovers she's pregnant unexpectedly. Her friends and family are in shock at first but then rally around to support her. Maybe the father of the baby is a mysterious character, adding an element of intrigue to the story.
I'm not entirely sure if there is a specific well - known fanfiction with Naruto as Mavis' father. There are so many fanfictions out there, and it could be a very niche or new concept. However, given the creativity of fanfiction writers, it's not impossible that someone has written a story with this premise. Maybe it involves some kind of magical or time - traveling plot device to make such an unlikely connection between the two characters from different universes.
There's great potential in a Naruto and Mavis Vermillion fanfiction. Naruto's journey of self - discovery and growth can be paralleled with Mavis' own story in the Fairy Tail world. They both have had to overcome great hardships. For example, Naruto was an outcast in his village at first, and Mavis had to deal with the loss of her loved ones. In a fanfiction, they could find common ground in their shared experiences and help each other move forward.
One possible fanfiction could be that Natsu and Mavis get married in a simple yet magical ceremony. Their friends from Fairy Tail are all present, and the guild hall is decorated with beautiful flowers. Natsu is nervous but excited, and Mavis looks stunning in her white dress. After the wedding, they embark on a journey together to explore new lands and discover hidden magic, all while growing closer as a married couple.
In this fanfiction, Natsu and Mavis' married future could be one where they build a small cottage near the guild. They have a peaceful life, with Natsu going on occasional guild missions while Mavis stays back to tend to their home and garden. Their days are filled with simple joys like cooking together and sharing stories by the fireplace at night.
Well, in many fanfictions, their relationship might start with Natsu being a bit in awe of Mavis as she is a very important figure in Fairy Tail's history. Natsu, being his brash self, might initially make mistakes around her but gradually learns from her wisdom. As time goes on, he could come to respect her even more deeply and they might form a bond where Mavis becomes like a guiding light for Natsu in his adventures and growth within the Fairy Tail guild.