In this fanfiction, Marcus could start as an outsider in the Naruto world. But as he gets involved in their conflicts, he realizes that the Digimon and Naruto's world share some similarities in terms of protecting their own. His presence could also introduce new technology or magic (from the Digimon world) that could help Naruto in his fight against stronger enemies. For instance, Digimon evolution could inspire Naruto to develop new forms of his jutsu.
Marcus could be a bridge between the two worlds. Since he's from the Digimon world, he could introduce the concept of Digimon to the Naruto characters. His combat skills and the bond with his Digimon could be something that Naruto and his friends look up to.
One idea could be that Marcus from Digimon somehow gets transported to the Naruto universe. He could use his Digimon partner's abilities to interact with the ninja world. For example, his Digimon might have unique powers that could be useful in battles against ninja techniques.
Well, Rayquaza could be the key to a mystery in the crossover fanfiction. Maybe there are ancient scrolls in the Naruto world that mention a powerful sky - dragon - like creature, which is actually Rayquaza. When some Pokemon trainers from the Pokemon world end up in Naruto's world, they recognize the signs of Rayquaza's presence. Naruto, intrigued by these new visitors and the mystery of Rayquaza, joins them on a quest to find Rayquaza. Once they find it, Rayquaza helps them bridge the gap between the two worlds and they all work together to fight a common enemy that is trying to use the chaos of the two worlds colliding for their own evil purposes.
Maybe Marcus and Thomas get transported to a strange and unknown part of the Digital World. There, they face challenges that test their friendship. For example, they might encounter a situation where they have to choose between their own goals and the well - being of the other. As they work through these issues, they grow closer and become better Digimon tamers.
A plot might involve the Digimon coming to the Naruto universe. The Digimon's digital powers could be seen as a new form of jutsu. Some of the ninja might be suspicious of the Digimon at first, but then they realize that they can work together. For instance, a Digimon with the ability to fly could help the ninja in scouting missions, and in return, the ninja could teach the Digimon about stealth and strategy.
Another plot could be that there is a common enemy that threatens both the Digital World and the Naruto world. So, Naruto and some of his ninja friends, along with a group of Digimon, have to work together. Naruto's shadow clones could be used to create diversions while the Digimon attack from different angles. And the Digimon's ability to evolve could give them an edge in battles against the powerful enemies that they face together.
She could fit in as a specialist in the supernatural. The Avengers often deal with high - tech threats, but Buffy's expertise in the world of demons and magic would be a fresh addition. She could be the one to handle the more 'creepy - crawly' threats that the Avengers might not be fully equipped for.
Well, Sora could potentially be a new type of ninja. Maybe he has some unique jutsu that the Naruto world has never seen before. For example, if he has powers related to light, he could use it in combat against the various villains in the Naruto universe like the Akatsuki. His character could also bring in new storylines, such as his origin being a mystery that Naruto and his friends have to uncover.
He could fit in as a new and powerful hero. His unique abilities like the ability to transform into a nine - tailed fox form would be a huge asset. The heroes in the Marvel universe would be both amazed and cautious of his power. For instance, Thor might see Naruto as a worthy ally with his own god - like status in the Naruto world.
Kaguya can be a powerful and mysterious element in the crossover. She could be a catalyst for change. For example, her powers might attract the attention of the various factions in DxD, leading to conflicts or alliances.
One possible title could be 'The Bond of Marcus and Thomas in the Digimon World'.