One great 'Naruto Crossover Overlord' fanfic is 'Naruto in the World of Overlord'. It has an interesting plot where Naruto is transported to the Overlord universe and has to adapt to its rules and power systems. His ninja skills create a unique dynamic in the new world.
Character interactions are also unique. For example, Naruto's positive and determined personality clashes and then meshes with the often more complex and morally grey characters in the Overlord world. This can lead to some really interesting character development arcs, like a cynical Overlord character starting to believe in Naruto's ideals of friendship and hard work.
Well, a cool plot could be a fusion of the two power systems. Imagine if ninjas in the Naruto world could learn some of the magic from Overlord. It would completely change the balance of power. Or perhaps the Akatsuki organization teams up with some of the villains in Overlord to take over both worlds. They could combine their resources and knowledge to create a really powerful and evil force. Also, there could be a story where a character from Naruto, like Sasuke, tries to master the power of the Overlord world to become even stronger and seek revenge in a new way.
If we consider the abilities of the characters in a Naruto - Overlord crossover. Naruto's shadow clones could be used in interesting ways in the Overlord world. For instance, they could be used as decoys in battles against powerful undead or magical creatures. In return, the magic of the Overlord world could be used to enhance the clones, like giving them temporary magical shields. Also, the Overlord's ability to control undead could be combined with some of the mind - control jutsu from Naruto, creating a really unique and powerful form of domination over enemies.
In a Naruto - Overlord crossover fanfiction, a great plot twist would be if the Ainz Ooal Gown guild members thought that the Sharingan was a powerful and unknown form of magic. They might try to study it or even recruit Sasuke, who has the Sharingan, into their ranks. This would create a complex situation where Sasuke has to decide between his loyalty to Konoha and the allure of the new and powerful world of Overlord.
Yes, there are likely some 'Naruto is Overlord' fanfictions out there. Fanfiction writers often like to combine different popular universes in creative ways. You can try searching on major fanfiction websites like Fanfiction.net or Archive of Our Own to find such works.
One common theme is the exploration of Shalltear's power. Since she's a very powerful character in the Overlord universe, many fanfictions like to test her limits when she's in a crossover situation. Another theme is loyalty. Shalltear's loyalty to Ainz is a big part of her character, and in crossovers, this loyalty often gets challenged or reaffirmed in different ways. For example, in some crossovers, she has to choose between following Ainz's commands and doing what she believes is right in the new world she's in.
Well, there's a 'Overlord Crossover Fanfiction' that combines it with 'Fullmetal Alchemist'. In this, the alchemic concepts of 'Fullmetal Alchemist' are pitted against the magic and power structures in Overlord. It's really cool to see how the characters from both worlds adapt to each other's rules. There's also a crossover with 'Attack on Titan' which brings in the element of the Titans into the world of Overlord, creating a lot of intense and unique battle situations.
One idea could be an Overlord crossover with Sword Art Online. You could have the powerful beings from Overlord enter the virtual world of SAO and cause chaos among the players. They might see the game world as a new territory to conquer or just a place for some interesting 'experiments'.
It's hard to say. Ainz Ooal Gown has a vast array of powerful magic spells at his disposal. However, Ben when he transforms into Alien X could be extremely powerful as well. Alien X has reality - warping abilities. But Ainz has his intelligence and strategic thinking. So it could really go either way depending on the situation.