A possible plot could be set in a parallel universe where Wendy is not a villain. She and Luigi meet at a grand Mushroom Kingdom festival. They both share a love for a particular type of mushroom - based food that is rare at the festival. As they search for this food together, they face various challenges like competing with other characters for the last piece, and through these shared experiences, they fall in love.
Their relationship could develop through shared interests. For example, if they both have an interest in exploring the more mysterious parts of the Mushroom Kingdom. They could start going on adventures together, and as they face challenges like tricky terrains or new enemies, they rely on each other and grow closer.
One idea could be that Mario and Luigi find a magical world that only they can enter together. In this world, they have to solve puzzles that require their unique skills as a team. For example, Mario's jumping ability and Luigi's higher jump and ability to float a bit could be combined to reach new heights and unlock secrets.
One idea could be that Luigi and Tails team up to solve a mystery in a strange, hybrid world that combines elements from their respective universes. They could use Tails' mechanical skills and Luigi's courage to face unknown challenges.
Maybe in the fanfiction, there is a magic spell that fuses Naruto and Wendy's powers together. This new power is needed to defeat an ancient evil that is awakening. They have to learn to control this combined power and also deal with the cultural differences between the ninja world and the Fairy Tail world. For example, Naruto is used to stealth and quick strikes, while Wendy is more accustomed to magical battles in open areas.
They could team up to take down a powerful and corrupt organization in the Gun x Sword world. Van's strength and Wendy's intelligence would be key assets in this fight.
One interesting plot idea could be Wendy and Erza teaming up for a special mission that no one else can handle. Maybe they have to go into a dangerous, enchanted forest where magic behaves strangely. Along the way, Wendy's healing abilities and Erza's combat skills complement each other, and they start to understand each other on a deeper level, forming a strong friendship that could potentially turn into something more in the eyes of the readers.
One idea could be that Mario and Luigi get transported to a strange new world where the rules of their own world are all mixed up. They have to use their combined skills in a whole new way to find their way back home. For example, Luigi might have to be more brave and take the lead in some situations while Mario has to use his speed in different ways than he's used to.
One idea could be that Mario and Luigi find a magical lemon tree in a hidden part of the Mushroom Kingdom. The lemons from this tree have special powers that they have to figure out how to use to save the kingdom from a new villain. For example, the lemons might give them temporary super strength or the ability to fly. Another plot could involve Luigi accidentally getting lost in a lemon - themed dimension while trying to find a rare ingredient for a recipe. Mario then has to brave this strange new world filled with lemon - based creatures to rescue his brother.
One idea could be that Luigi and the fem minions team up to save a magical kingdom. Luigi uses his skills like jumping and plumbing knowledge while the fem minions use their unique abilities and mischievousness to outwit the villains. Another could be a story where they all enter a cooking competition together, Luigi providing the human touch and the fem minions adding their own zany ingredients and cooking styles.
One idea could be that Female Bowser is initially set on causing chaos but Luigi manages to show her a different side of life. Maybe he takes her to a peaceful meadow and they have a heart - to - heart conversation. This could lead to her having a change of heart and helping Luigi protect the Mushroom Kingdom instead of attacking it.