One idea could be that Pauline gets kidnapped by Bowser and Mario has to go on an extra challenging adventure to save her. He might face new types of enemies and obstacles along the way.
Another concept could be a story set in an alternate universe where Pauline is the one with the super jumping abilities instead of Mario. She teams up with Mario, who has some other unique skills like being able to communicate with certain creatures, and they embark on a journey to save the Mushroom Kingdom from a different kind of threat.
Perhaps Pauline could discover a magical power that she uses to help Mario in his quests. For example, she could have the power to make plants grow rapidly to block enemies or create bridges. This would add a new dynamic to their relationship as they work together.
One great 'Mario x Pauline fanfic' could be about their adventures in a new, undiscovered kingdom. Maybe they team up to rescue the Toads who have been kidnapped by a new villain. In this fanfic, Mario's bravery and Pauline's intelligence could be highlighted as they face various challenges like tricky platforming sections and puzzles.
A theme of discovery is also quite prevalent. They might discover new power - ups, hidden areas, or secrets about each other. For example, Pauline could discover a hidden ability within herself while Mario might find a new way to defeat enemies. The fanfics also often have a theme of overcoming challenges, whether it's big bosses or difficult terrains.
You can start by looking on fanfiction websites such as Archive of Our Own (AO3). It has a large collection of fan - created works, and there's a good chance you'll find some 'Mario x Pauline fanfic' there. Just use the search function and type in the relevant keywords.
There's also 'Mario and Pauline: A New Odyssey'. In this fanfic, the author explores the idea of Pauline having special powers that she discovers during her journey with Mario. It's a bit different from the usual Mario stories and gives Pauline a more central role, which is really interesting.
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.
Another plot could be that Bowsette accidentally casts a spell that makes Mario forget all about his previous adventures and relationships. Bowsette then has to re - introduce herself to Mario and try to make him fall in love with her from scratch. This would involve her showing him the beauty and magic of the Mushroom Kingdom in a new light, while also facing challenges from other characters who are suspicious of her motives.
A theme that pops up a lot is heroism. Mario is his usual heroic self, and Pauline often shows her own brand of courage too. They work as a team to overcome challenges. Also, friendship can be a theme, as their relationship can start as friends and develop into more.
One great mario x pauline fanfiction is 'A New Adventure for Mario and Pauline'. It has a really engaging plot where they team up to save the Mushroom Kingdom from a new threat. The story does a great job of showing their relationship develop.
One idea could be that Naruto gets transported to the Mario world. He might use his ninja skills to help Mario and Luigi in their battles against Bowser. For example, Naruto could use his Shadow Clone Jutsu to confuse Bowser's minions while Mario goes for the power - up.
You could write a Paper Mario fanfic that involves time travel. Mario goes back in time to prevent a great disaster that happened in the past of the Paper Mario world. This could lead to him interacting with past versions of characters and changing the course of history in unexpected ways. Or, a fanfic about a new villain that only exists in the paper realm and has unique powers that Mario has to figure out how to defeat.