A great pairing would be Obi - Wan Kenobi and Black Panther. Black Panther has his own unique culture and technology in Wakanda. Obi - Wan could be fascinated by it. They could fight side by side against an enemy that is after Wakanda's vibranium and also has some connection to the Sith or the dark side of the Force. Obi - Wan could use his lightsaber skills, and Black Panther could use his enhanced strength and claws. They would make a formidable duo.
I think pairing Obi - Wan Kenobi with Scarlet Witch would be really interesting. Scarlet Witch has her powerful magic, and Obi - Wan has the Force. They could learn from each other's abilities and powers. Maybe Scarlet Witch could help Obi - Wan understand some different aspects of magic that are similar to the Force, and Obi - Wan could teach her about self - control and discipline in using power.
One possible plot could be that Obi - Wan somehow gets transported to the Marvel universe. He meets Doctor Strange, who senses his strong connection to the Force. Together, they team up to fight against a new dark force that is threatening both the Jedi way and the safety of the Marvel universe.
In Obi - Wan Kenobi crossover fanfiction, Qui - Gon Jinn is a common character to be paired with him. They could be in a crossover where they have to face a new and powerful enemy that requires both their skills and knowledge. Darth Vader (Anakin after his fall) is also often paired. This creates a very interesting dynamic as Obi - Wan has to deal with his former apprentice in a different context, perhaps in a world full of steampunk technology. Leia Organa can be paired with Obi - Wan too, where she learns more about her connection to the Force and her father from Obi - Wan in a crossover with a space - faring civilization different from the Star Wars galaxy.
Darth Maul and Wolverine would be an intense pairing. Darth Maul's double - bladed lightsaber skills against Wolverine's adamantium claws and healing factor would be a brutal and exciting fight. Also, their dark and brooding personalities have some similarities.
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.
Ezra Bridger would be a great character to pair with Obi - Wan. Ezra is still learning about the Force, and Obi - Wan could be his wise mentor, teaching him more advanced techniques and the true nature of the Force.
Hellboy and Wolverine would be a really interesting pair. Wolverine's feral nature and regenerative abilities combined with Hellboy's brute strength and demonic heritage would make for some great action scenes. They could have some really cool banter too, with Wolverine's gruff attitude and Hellboy's dry sense of humor.
One interesting pairing could be Godzilla and Hulk. Both are powerful, almost indestructible forces of nature. They could have an epic battle at first, as they both have a tendency to lash out when provoked. But then they could end up teaming up against a greater threat, like a powerful alien invasion. Another great pairing would be Godzilla and Iron Man. Iron Man could use his technology to study Godzilla, and perhaps even try to create some sort of armor inspired by Godzilla's abilities. And Godzilla could provide a physical presence that Iron Man could rely on in a fight. Also, Godzilla and Thor could be a fascinating pair. Thor's god - like powers and connection to nature could be paralleled with Godzilla's own primordial power. They might have a mutual respect for each other's strength.
Thor and a Dwarf Lord would be really interesting. Thor with his god - like powers and his hammer Mjolnir could team up with a Dwarf Lord, who is known for his skill in forging and combat. They could exchange stories about their great battles and also work together to create some powerful weapon, perhaps using Asgardian and Dwarven forging techniques.
I think Annabeth and Black Widow would be an interesting pair. Both are strong, intelligent women. Annabeth's strategic mind from her demigod training could work well with Black Widow's spy skills. They could be on a mission to infiltrate a secret lair that has something to do with both the Greek and Marvel worlds.
Another interesting pairing could be Ben and Captain America. Cap's leadership and moral compass could influence Ben, while Ben's diverse powers could be a great asset to Cap in battle. They could be in a situation where they have to fight against a mind - controlled army, and Ben's aliens like Big Chill could freeze the enemies in place while Cap gives strategic commands.