Another possible pairing could be Sasuke and Elsa. Sasuke has his own dark past and a brooding personality. Elsa also has her own internal struggles with her powers. They could bond over their shared experiences of having to control something within themselves that others might fear. And their cool and somewhat aloof demeanors could make for an interesting dynamic.
It's also possible to pair Naruto with Anna. Anna's adventurous spirit and her loyalty would mesh well with Naruto. They could go on adventures together in both the Naruto world and Arendelle. Naruto could show Anna the ropes of being a ninja - like adventurer, and Anna could introduce Naruto to the joys of the Arendelle lifestyle.
Naruto and Bella could be an interesting pair. Naruto's energetic and positive nature could contrast with Bella's more introverted and moody self. It could create a unique dynamic where Naruto tries to cheer up Bella and she, in turn, shows him the more complex emotional side of the Twilight world.
Well, I think Green Lantern and Rock Lee would be an interesting pair. Green Lantern's power of creating constructs with his ring could be used in creative ways along with Rock Lee's taijutsu. Also, Wonder Woman and Hinata could be paired. Wonder Woman's combat skills and Hinata's Byakugan - enhanced fighting style would make for a great combination. And Flash and Kiba with his dog Akamaru could be a fun pair, with Flash's speed and Kiba's speed - based ninja techniques.
Naruto and Bart could be a likely pair. Both are mischievous in their own ways. Naruto is always getting into trouble with his pranks in the ninja academy, and Bart is constantly causing chaos in Springfield. They could get up to all sorts of antics together, like pulling pranks on the other characters in both universes.
Sasuke and Sein could be an unexpected but fascinating pair. Sasuke's brooding and powerful presence might contrast with Sein's pure and guiding spirit. Their interactions could lead to some great character development for both of them.
I think Hinata and Rias could be paired up in some way. Hinata's gentle nature and her strong loyalty could complement Rias' leadership and determination. They might form an unexpected friendship or even a strategic alliance within the fanfiction's plot.
Ruby could be paired with Eragon. Ruby's leadership and combat skills along with her silver eyes' power could complement Eragon's dragon - rider abilities. They could go on quests together, with Ruby's speed and Eragon's dragon - powered flight making them a formidable team.
Sasuke and Tex might be likely to be paired up. Both are strong and somewhat brooding characters. Sasuke's quest for power could be paralleled with Tex's own abilities and her role in the Red vs Blue universe. They might engage in some intense battles or even end up having to work together against a common enemy, leading to some interesting character development for both of them.
Harry and Naruto are often paired as they are both the main protagonists in their stories and share the 'chosen one' archetype. Hermione and Sakura are also popularly paired, as they are both intelligent and strong female characters. Another common pairing is Ron and Choji, perhaps because they both have a bit of a comical side and are loyal friends. Also, Dumbledore and the Third Hokage could be paired in some fanfics, as they are both wise leaders in their worlds.
Well, Clarisse might be paired with a more aggressive Doom character. She's a fierce warrior in the Percy Jackson series. They could form a powerful duo, fighting side by side against the common enemies. Also, Tyson could be paired with a strong, hulking character from Doom. Tyson is a Cyclops with great strength, and finding a counterpart in Doom that shares that physical power would create an interesting dynamic in the fanfiction.
The Doom Slayer and Commander Shepard are likely to be paired. They are both iconic heroes in their respective universes. Shepard is a strategic leader, while the Doom Slayer is a force of pure destruction. Their interactions could lead to some really interesting storylines.