One possible plot could be that they meet during a time - travel incident. Obi - Wan from the Star Wars universe and Kakashi from the Naruto universe find themselves in a neutral dimension. They initially see each other as threats but then realize they have a lot in common as both are highly skilled warriors and mentors. They then team up to find a way back home.
Yes, there are some really interesting ones. You can start by looking on popular fanfiction websites like Archive of Our Own. Just search for 'obi wan meets kakashi' in the search bar and you'll get a list of relevant stories. Some might focus on their different fighting styles coming together in an epic battle, while others could explore a more friendship - based encounter.
One interesting plotline could be a battle that takes place in an alternate universe where Anakin and Obi - Wan have different allegiances from the start. Maybe Anakin is a Sith Lord right from the beginning and Obi - Wan has to face his former apprentice in a more cut - throat battle.
Anakin and Obi - Wan could fit into a Marvel fanfic if they were part of a multiverse - spanning story. The Marvel universe already has concepts like the multiverse. They could be brought in as representatives of a different kind of power (the Force). Anakin's emotional and sometimes unpredictable nature could create interesting dynamics with the more stable Marvel heroes. Obi - Wan could act as a mediator between the two universes, using his knowledge of the Force and his diplomatic abilities to navigate the complex relationships in the Marvel world.
Well, Anakin is often very well - written. His internal conflict between the light and dark side can be explored in great detail. His complex relationship with Obi - Wan, from being a beloved apprentice to a bitter enemy, gives a lot of room for character development. Writers can show his journey from a hopeful Jedi to a conflicted individual on the verge of falling to the dark side.
Well, it could be really chaotic. Maybe Anakin and Obi - Wan would be mistaken for new superhumans in the Marvel universe. Their lightsabers would be seen as some sort of high - tech weapons. They might end up getting involved in the Avengers' battles, either as allies or foes depending on how the story is written. Anakin's power could be compared to that of Scarlet Witch, and Obi - Wan's wisdom might be on par with Doctor Strange's.
There may not be mainstream, widely - publicized fanfictions with Obi - Wan gagged. But some independent writers might have created stories around this concept. It could be that in a story, Obi - Wan is gagged during a diplomatic mission turned hostile. His captors want to silence him to gain an advantage in negotiations. This could lead to a complex plot where his friends have to use their wits and skills to free him and resolve the diplomatic crisis.
Well, in some fanfictions, the battle might start as a misunderstanding. Spiderman could be in Gotham chasing a bad guy who has a connection to New York and Batman mistakes him for a new threat. In this case, Spiderman would try to explain himself but Batman, being the brooding detective, might not listen. Then there are scenarios where the battle takes place in a neutral location like an abandoned warehouse. Here, both of them have to rely on their skills and resources. Spiderman would use his webs to create obstacles and Batman would use his gadgets to break through them. Also, there could be a scenario where they team up against a greater threat first and then due to a clash of egos, they end up fighting each other.