If it's a crossover with Final Fantasy, Cloud Strife could be a main character. He could bring his sword - fighting skills to the Mario Party world. His serious and brooding personality would contrast with the more light - hearted Mario characters, creating some interesting interactions during the story and mini - games.
In a crossover with Animal Crossing, Tom Nook could be a main character. He could run some of the mini - games that involve trading or building. His business - minded nature would add a different flavor to the Mario Party. He might be trying to make a profit from the mini - games or trading items with the other characters.
Another option could be an evil version of Princess Peach. She could be possessed by some dark force. This would be a very interesting antagonist as Mario and Luigi would be hesitant to fight her at first because of their loyalty to the real Peach. But as she causes more and more chaos, they'd have to find a way to save her and the kingdom without harming her.
One idea could be a crossover with the Legend of Zelda series. Link could be a special guest in the Mario Party world, bringing his unique items like the Master Sword and Hylian Shield. He might participate in mini - games that require his combat skills or puzzle - solving abilities.
Mario and Luigi are of course very popular as they are the main characters of the Super Mario series. Their well - known personalities and abilities make them central figures in most crossovers.
It could be Bowser who has somehow gained the power of a powerful ninja jutsu. He uses this new - found power to take over both the Mushroom Kingdom and start invading the Naruto world. His fire - breathing ability combined with ninja techniques would make him a formidable foe for Naruto and Mario.
Perhaps some of the more mysterious characters from the series could take the lead. For example, Isabel Kabra. Her devious nature could add a whole new layer of intrigue to the crossover fanfiction. She could be working with or against the other characters in unexpected ways, creating a lot of tension and interesting plot twists.
A group of scientists who were involved in creating the Indoraptor in the first place could be main characters. They might have to face the consequences of their creation when it crosses over into another world or situation. They would be trying to either control it or destroy it.
If it's a crossover with the DC universe, Batman could be the main character. He would use his detective skills and arsenal of gadgets to face the Deathclaw. His dark and brooding nature would make for an interesting contrast against the brute force of the Deathclaw.
Bowser is a prominent and popular character in super mario bros crossover fanfiction. He can be a great antagonist in crossovers, whether he's teaming up with other villains from different franchises or going against new opponents. Kirby is also popular. His ability to copy abilities can lead to some really fun and creative crossovers with the Super Mario Bros characters. And of course, Donkey Kong is a classic character that is well - liked in these crossovers. His strength and connection to the Mario franchise's early days can be explored in new and interesting ways.
Mario and Sonic are at the top of the list for sure. But in addition to Luigi and Tails, Princess Peach is often included. She can bring an element of needing to be rescued or she could also be a strong character helping out. Knuckles from Sonic's world is also popular. He has his strength and knowledge of the Chaos Emeralds, which can be crucial in a crossover story. There are also some fans who like to include Bowser and Dr. Eggman as the main antagonists, which makes for an exciting story.
Mario and Luigi are always popular as they are the mainstays of the Mario Kart series. But when it comes to crossovers, Sonic is a top pick. His popularity and speed make him a great addition. Link from The Legend of Zelda is also a common choice. His unique look and abilities can add a different flavor to the races.