Definitely Superboy and Captain America. Superboy with his super strength and sometimes - confused sense of self could learn a lot from Captain America's strong moral compass and leadership. Another interesting pairing would be Robin and Black Widow. Robin's detective skills combined with Black Widow's espionage expertise could make for some really cool stealth and information - gathering missions.
I think Thor and Superman would be a very interesting pairing. Thor is a god with his hammer and lightning powers, while Superman is an alien with super strength, flight, and heat vision. They could have some great battles testing their strength and then team up to take on a powerful foe like Doomsday or Ultron. Their different personalities, Thor's more brash and Superman's more moral, would also create an interesting dynamic.
One of the most interesting pairings would be Black Widow and Catwoman. They are both skilled in stealth and combat. Black Widow's training as a spy and Catwoman's thieving skills could lead to some really cool heist - like scenarios within the crossover story. And then there's Hawkeye and Green Arrow. They are both expert archers and sharpshooters. It would be great to see them compare their skills and work together in a battle situation.
Definitely Superboy from Young Justice and Black Lightning from the Outsiders. Superboy has his super - strength and Kryptonian - like abilities, while Black Lightning has his electrical powers. Their different personalities, with Superboy being more brash and Black Lightning more experienced and level - headed, could lead to some great character - development moments and interesting interactions.
Definitely Naruto and Iron Man. Naruto is this energetic, determined ninja, and Iron Man is this brilliant, sarcastic inventor. Their personalities are so different yet they could learn a lot from each other. Iron Man could be intrigued by Naruto's chakra system and try to replicate it in some way, while Naruto would be fascinated by all of Iron Man's high - tech gadgets.
Supergirl and Black Widow would be a great pairing too. Black Widow could teach Supergirl some stealth and espionage skills, while Supergirl could show Black Widow the power of flight and super - strength. They could also bond over their experiences of being different in their respective worlds.
I think Thor and Wonder Woman would make an amazing pair. They both come from god - like lineages. Thor with his Asgardian powers and Wonder Woman with her Amazonian and divine powers could have some epic battles together against common foes. Their different yet powerful fighting styles would complement each other well.
For an Arrow - Avengers crossover fanfiction, some really interesting character pairings could emerge. For instance, Malcolm Merlyn and Loki. Malcolm is a master manipulator and Loki is the God of Mischief. They could either team up to cause chaos or be in a constant battle of wits. Also, Cisco Ramon from The Flash (since he often crosses over with Arrow) and Bruce Banner. Cisco could be fascinated by Banner's scientific knowledge and Banner could be interested in Cisco's work on the multiverse. And of course, Quentin Lance and Nick Fury. Quentin, as a police detective, and Nick Fury, as the head of S.H.I.E.L.D., could share their insights on how to keep their respective cities and the world safe.
Definitely Daredevil and Black Widow. Daredevil's enhanced senses and martial arts skills combined with Black Widow's espionage expertise and combat abilities would make for an exciting duo. They could work together on a stealth mission, with Daredevil using his senses to detect hidden threats and Black Widow using her gadgets and charm to get them in and out of dangerous situations.
I think Master Chief and Captain America would be an interesting pairing. Master Chief is a super - soldier in his own right from a high - tech future, while Captain America is a super - soldier from the past. Their different combat styles and values would create an interesting dynamic.
Another great pairing would be Superman and Captain America. Superman is an alien with god - like powers, while Captain America is a human with peak physical and moral strength. Cap could teach Superman about the value of human tenacity and leadership on a more down - to - earth level. And Superman could show Cap what true superhuman power looks like. They could work together to inspire the rest of the Avengers and any other heroes they encounter in a battle.