Well, Natsu could teach young Mavis some new combat moves. Since Natsu is known for his physical strength and combat skills in the Fairy Tail guild. He might show her how to better defend herself. For example, he could teach her some basic hand - to - hand combat techniques combined with his fire magic for added effect.
One possibility could be that Natsu is on one of his adventures and stumbles upon a young Mavis in a magical forest. Their meeting could be filled with wonder as Natsu shows Mavis some of his cool fire magic tricks, and Mavis, in turn, shares some of her early knowledge of magic. It could be the start of an interesting friendship that defies time and space in the Fairy Tail universe.
In a 'Goku meets Natsu' fanfiction, they might start off by being confused about each other's powers. Goku could be intrigued by Natsu's fire - based magic, while Natsu would be amazed at Goku's super Saiyan strength. They could end up having a friendly sparring match to test each other's skills.
In a 'naruto meets natsu fanfiction', they might start off as rivals. Naruto, with his ninja skills and determination, and Natsu, with his dragon - slayer strength. But as they get to know each other better, they realize they have a lot in common. For example, they both have a strong sense of loyalty to their friends. So they end up becoming good friends and combining their powers to protect their respective worlds from threats that could endanger both.
The fanfiction might start with Natsu's search for his mother. When they meet, there could be some initial shock or disbelief. His mother could look at him with great love and pride. They might have a long conversation about his life so far, his friends, and his adventures. She could also introduce him to parts of his heritage that he was previously unaware of, which could shape his future actions and decisions in the story.
In the 'natsu meets his parents fanfiction', Natsu may initially be in shock when he meets them. His parents could look exactly like him or have some unique features. They might take him on a journey to a place that was important to their family. Along the way, Natsu could learn valuable lessons about family, love and self - discovery.
In this kind of fanfiction, Natsu might have some really interesting interactions. He could try to warn his past self about future challenges or mistakes. For example, he might tell his younger self about a particularly difficult battle and how to better prepare for it.
In the 'natsu meets his future self fanfiction', one possibility is that his future self warns him about certain events that are going to happen. For example, about an upcoming battle that is more dangerous than any he has faced before. His future self could also show Natsu new magic techniques that he will develop over time. It could also be a situation where Natsu's future self is not what he expected, perhaps having made some mistakes that Natsu now has the chance to avoid.
Well, in this fanfiction, Natsu might have some epic battles with the members of the Seven Deadly Sins. Maybe he'll learn new powers from them or they'll team up to fight a common enemy.
In this fanfiction, Morty might be really shocked at first to meet a young Rick. He could be confused about how this young version of Rick behaves compared to the Rick he knows. Maybe they'll go on some wacky adventures together that are different from the ones Morty has with the regular Rick.
If Young Justice meets the Avengers in fanfiction, the cultural differences between the two groups could also be a factor. Young Justice is more of a teen - led group with its own set of values and goals. The Avengers are a more global - scale superhero team. Aqualad could share his knowledge of underwater threats with Namor if they ever interact. And there could be some misunderstandings at first, like when the Flash from Young Justice might accidentally run into Hawkeye's arrows during a fight against a common foe.