Diggle and Derek Morgan would be an interesting combination. Diggle is Oliver's right - hand man, a military - trained and very loyal friend. Derek Morgan is a tough FBI agent with a strong sense of justice. They could team up on the more physical aspects of a case, like going undercover or chasing down suspects. Their conversations could be filled with military - style banter and mutual respect for each other's skills.
Oliver Queen and Spencer Reid would be an interesting pairing. Oliver is a man of action, used to taking risks and making quick decisions in the heat of battle. Spencer, on the other hand, is highly intelligent and more cerebral. Their interactions could be really cool. Oliver could learn a lot from Spencer's vast knowledge, and Spencer could gain some confidence in more physical situations from Oliver.
Felicity Smoak and Penelope Garcia would make a great pair. They are both tech - savvy characters. Felicity is more hands - on with the hacking and building of tech devices in Arrow, while Penelope is the master of all things digital in the BAU. They could bond over their love for technology, share tips and tricks, and maybe even work together to track down a cyber - criminal in the fanfiction.
Gibbs and Hotchner would be an interesting pairing. Gibbs is a tough - as - nails leader in NCIS with a lot of field experience and a unique way of getting information out of suspects. Hotchner, on the other hand, is a more by - the - book leader in Criminal Minds who is also very good at handling his team. In a crossover, they could learn from each other's leadership styles while working on a case that requires both military and psychological expertise.
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 Oliver Queen and Jim Gordon. Oliver is used to operating in the shadows and taking justice into his own hands in Starling City, while Jim is a cop trying to uphold the law in the corrupt Gotham. Their different approaches to crime - fighting would make for some great interactions.
Oliver Queen and Dean Winchester would be an interesting pairing. Oliver is a brooding, justice - seeking vigilante, and Dean is a tough, monster - hunting badass. They both have a sense of loyalty to their causes and a no - nonsense attitude. They could bond over their shared experiences of losing loved ones and their determination to protect the innocent.
Shadow the Hedgehog and Cerebella would be a fascinating match - up. Shadow's brooding and mysterious nature could be intrigued by Cerebella's confident and somewhat flamboyant fighting style. They might start off as rivals, constantly trying to outdo each other in combat, but gradually come to respect each other. Shadow could learn to be a bit more open from Cerebella, while Cerebella could learn the value of Shadow's more strategic and calculated approach to battles.
Alucard and Dean Winchester would be an interesting pairing. Alucard's dark and brooding nature, combined with his overpowering abilities, would contrast with Dean's more impulsive and human - centered approach.
Sherlock and Rossi would have a very engaging interaction. Rossi has years of experience in profiling and investigating, and Sherlock has his unique deductive abilities. They could sit down and exchange stories of their most difficult cases, and perhaps Rossi could offer some insights into the psychological aspects of cases that Sherlock might overlook. And on the other side, the interaction between Sherlock and JJ from Criminal Minds could be interesting. JJ's skills in communication and dealing with the media could play an important role when they are working on a high - profile case together.
Another interesting pairing would be Captain America and Oliver Queen. Both are leaders with a strong sense of justice. They could have some great discussions about what it means to be a hero and how to lead a team. And when it comes to fighting, they could show off their different combat styles, with Cap's military - trained moves and Oliver's acrobatic and archery - based fighting.
The plot might involve a criminal who is using the same tactics as some of the villains in Arrow's world. The Criminal Minds cast could be stumped until Oliver Queen shows up. He'd bring his own brand of justice and detective work. He could share his insights on how to track down a criminal who has a similar modus operandi as his enemies in Star City. They could then combine their resources, with the BAU's profiling skills and Oliver's street - smart and combat abilities to take down the bad guy.
Hermione Granger and Weiss Schnee could be a great pair. Hermione is highly intelligent and studious, while Weiss is refined and also has a great deal of knowledge. They could bond over their love for learning and perhaps work together on some sort of magical - mechanical hybrid project. For example, combining Hermione's magic knowledge with Weiss' understanding of Dust to create something entirely new.