What could be an interesting plot for a Naruto and Undertale crossover fanfiction?

Well, perhaps Bowser somehow makes a deal with some of the more malevolent characters in the Undertale world, like Flowey. Then Mario has to not only deal with Bowser but also the new threats from the Undertale realm. He might have to learn about the concept of LOVE and EXP in the Undertale world to fully understand how to defeat his enemies. And along the way, he could meet Sans and Papyrus, and they could have some really funny exchanges due to their very different personalities.

One interesting plot could be that the main character from DDLC, say, the protagonist, gets transported into the Undertale universe. They could start in the Ruins and interact with Toriel. Since the DDLC character is used to a different kind of world, their reactions to the monsters and the unique magic in Undertale would be fun to explore. Maybe they could try to use their knowledge from DDLC to solve some of the problems in Undertale, like trying to understand the nature of EXP and LOVE in the context of their own experiences.

One idea could be that Spider - Man somehow gets transported to the Underground in Undertale. He might initially be confused but quickly adapts his powers to the new environment. For example, he could use his webs to swing through the caverns and his spider - sense to detect approaching monsters. Maybe he teams up with Sans and Papyrus to fight against a common enemy, like a new, powerful and evil entity that threatens both the Underground and New York City in some way.

One idea could be that Naruto characters end up in the Underground world of Undertale. For example, Naruto with his determination could be seen as similar to the determination trait in Undertale. He might interact with Sans and Papyrus. Naruto could use his shadow clones to confuse the enemies in the Underground. Another idea is that the ninjutsu in Naruto could be combined with the magic system in Undertale. Maybe Sasuke's Sharingan could have an interesting interaction with the soul mechanics in Undertale.

Well, perhaps in this fanfiction, the SAO system is corrupted by an Orochimaru - like figure. He wants to use the virtual world to gain power and immortality. Naruto and his friends, along with the SAO players, have to team up. Naruto's positive attitude and never - give - up spirit inspire the SAO players. They all work together to defeat this new threat, with Naruto using his Rasengan in new and creative ways within the SAO world.

A plot could involve the Killzone characters getting access to chakra. Some of the Killzone soldiers might start to learn ninjutsu and this causes chaos in their own military structure. Meanwhile, Naruto has to figure out how to get back to his own world while also dealing with the new threats that this crossover has created. Maybe he teams up with some of the more honorable Killzone soldiers to find a solution.

A plot might involve Naruto being sent to Bayonetta's world. He'd be out of his element, but his determination would shine through. Bayonetta could mistake him for a strange demon at first. However, they soon realize they can help each other. Naruto's chakra could interact in unexpected ways with Bayonetta's magic. Together, they could face off against Bayonetta's foes, like the angels, with Naruto's Rasengan combined with Bayonetta's Witch Time abilities making for some epic battles.

In a Naruto and Spiderman crossover, it could start with Spiderman noticing some strange energy signatures in his city. These turn out to be Naruto's chakra flares. Naruto is there looking for a way back to his own world after being accidentally sent to Earth - 616 (the Marvel Universe). They meet and at first don't understand each other. However, when they see a common enemy, a group of ninjas - like mutants who are causing chaos, they decide to work together. Spiderman uses his agility and web - shooting while Naruto uses his jutsu to defeat the bad guys.

One possible plot could be that Naruto and his team are on a mission in a strange new land that turns out to be the world of Claymore. They encounter Claymores, the half - human, half - yoma warriors. Naruto, with his never - give - up attitude, tries to understand the complex relationship between humans and yoma in this world. He could end up befriending some of the Claymores and together they fight against a powerful common enemy that threatens both their worlds.

One possible plot could be that Guts from Berserk is somehow transported to the Naruto universe. He might initially be seen as a threat due to his menacing appearance and his large sword. However, as the story progresses, he could team up with Naruto and his friends to fight against a common enemy, like an Akatsuki member who has acquired some of the dark magic from the Berserk world. Guts' fighting skills and his ability to face the most terrifying foes could inspire Naruto and give him new perspectives on combat.