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.
Count Dooku could be a prominent character. Given his own fall to the dark side, he might be a mentor or a rival to Obi - Wan in the fanfiction. Mace Windu is another one. His strict view of the Jedi Code and his relationship with Obi - Wan could be explored in the context of Obi - Wan's turn. And of course, there are the various Sith Lords and dark side adepts that might surround Obi - Wan, either as allies or enemies in his new dark side life.
Often, Obi - Wan uses his mastery of the Force. He might use a Force - push to overpower his guards when they least expect it and then make a run for it. He could also use a mind trick on a high - ranking captor to order his release.
Well, Obi - Wan Kenobi has shown time and again his ability to adapt to different opponents. He defeated General Grievous, a formidable foe. Pong Krell, on the other hand, was consumed by his own dark desires. When it comes to a fight between them, Obi - Wan's use of the Force for defense and offense, his lightsaber skills which are refined over years of training, and his wisdom in combat situations would make him the victor. He can sense his opponent's moves and counter them effectively, something Krell's overconfidence might not be able to handle.
Jon Snow could be one. He has a sense of honor and leadership, much like Obi - Wan. They could bond over their shared values and Jon could learn from Obi - Wan's wisdom. Another could be Daenerys Targaryen. She is on a quest for power and Obi - Wan might see her as someone who needs guidance to use her power responsibly.