One interesting crossover could be the characters from Fairy Tail having to fight the Titans from Attack on Titan. For example, Natsu's fire magic could be used to take on the Titans in a really epic battle. His ability to quickly regenerate stamina might also give him an edge in the long - running battles against the Titans.
In some fanfiction, the Survey Corps from Attack on Titan might team up with Fairy Tail mages. They could learn from each other's skills. The Survey Corps could learn about magic, while Fairy Tail mages could learn about the strategic and combat techniques of the Survey Corps. This would create a really unique dynamic where two very different groups come together for a common goal, like saving the world from both Titans and any dark magic threats in the Fairy Tail universe.
Another idea in the fanfiction could be the exchange of technology and magic. The Attack on Titan world is very much based on steam - punk - like technology. So, perhaps the characters in Fairy Tail could introduce some of their magical items to the people in the Attack on Titan world. And in return, the Attack on Titan characters could share their advanced weaponry and ODM gear with Fairy Tail. This would lead to some really interesting storylines where characters have to adapt to new forms of power.
In a Pokemon - Attack on Titan fanfiction, we might see the Titan - shifters having an unexpected connection with certain Pokemon. Perhaps Eren's Titan form could be influenced by a powerful and rare Pokemon. Also, the different regions of the Pokemon world could be incorporated into the Attack on Titan universe. Like the Johto region could be a place where some of the Scouts find a special type of Pokemon that has a unique ability to counter the Titans.
One interesting crossover could be the Titans having Pokemon abilities. For example, a Titan might have the strength of a Machamp, with its multiple arms being like Machamp's powerful limbs. Another could be the Survey Corps using Pokemon to aid in their battles against Titans. Maybe they could have flying Pokemon like Pidgeot to scout ahead or fire - type Pokemon to attack the Titans' weak points.
In a crossover fanfiction, Naruto's sense of justice might conflict with Annie's actions in Attack on Titan. Naruto always tries to find a non - violent solution first, while Annie has been involved in some pretty brutal acts. This could lead to some great character development and interesting plot twists. Also, the different power systems of the three franchises could create unique battle scenarios, like a fight between Naruto's Rasengan and Annie's crystal - hardening abilities.
Well, in some fanfictions, you might see Edward Elric from Fullmetal Alchemist teaming up with Eren Yeager from Attack on Titan. They could combine their unique abilities. Edward's knowledge of alchemy and Eren's Titan - shifting power could be used to take on common enemies. For example, they might face a new threat that is a combination of the Homunculi from Fullmetal Alchemist and some new type of super - Titan in the Attack on Titan world. And the different character dynamics, like Edward's hot - headedness and Eren's determination, would make for an exciting story.
One interesting crossover could be the Jedi using their Force powers to combat the Titans in the world of Attack on Titan. For example, they could use the Force to predict the Titans' movements and dodge their attacks more effectively.
One interesting crossover could be the Autobots and Decepticons getting involved in the fight against the Titans. The Autobots' advanced technology could be used to create new weapons or defenses against the Titans. For example, their energy shields might be able to withstand the Titans' attacks. Another aspect could be the Transformers' ability to transform into different forms being used in strategic ways within the walls. Maybe a Transformer could transform into a large structure to block a Titan's path or into a flying vehicle to scout for Titans from above.
One interesting crossover could be the Titans invading Hogwarts. The students would have to use their magic in new and creative ways to defend against the massive Titans. For example, they could use spells like Wingardium Leviosa to lift debris and block the Titans' paths, or use the Patronus charm to create a powerful force that might stun or repel the Titans. Another aspect could be the characters from Attack on Titan learning about magic. Eren might be intrigued by the power of magic and try to incorporate it into his fight against the Titans. He could potentially team up with Harry Potter and his friends to find a new way to defeat the Titans once and for all.
A really cool concept could be the Warhammer magic items being introduced to the Fairy Tail world. Imagine if Gray got his hands on a Warhammer frost weapon. It could enhance his ice - make magic in ways he never thought possible. And the different magical lore from Warhammer could inspire new spells among the Fairy Tail mages.
In a Naruto x Attack on Titan fanfic, there could be a situation where the ninjas are brought into the world of Attack on Titan. Naruto himself could use his rasengan against Titans, which would be a very powerful weapon. The characters from Attack on Titan might be intrigued by the ninja's ability to use chakra and try to learn from them. This could lead to a new kind of training regime within the walls, where they combine their existing combat skills with the newfound chakra - based techniques.
Well, in some fanfictions, the immortality aspect might lead to really cool plotlines. Imagine Naruto characters like Sasuke or Kakashi becoming immortal and interacting with Fairy Tail's immortal characters like Zeref. They could exchange knowledge about their different forms of power and how to control their newfound immortality. Also, the guilds in Fairy Tail and the ninja villages in Naruto could form alliances based on this new shared situation of having immortal members.