Well, a cool concept for an Overwatch RWBY crossover fanfic would be to focus on the technology aspect. Overwatch has a lot of advanced tech, and RWBY has its own unique Dust - based technology. The fanfic could explore how the two types of technology interact. For instance, Mercy's healing staff could be affected by Dust in the RWBY world, or Torbjörn could use RWBY - style materials to upgrade his turrets. And of course, the character interactions would be great. Winston and Zwei could be an interesting pair to write about.
One of the most interesting pairings would be Reinhardt and Pyrrha. Reinhardt is a knight - like character in Overwatch, and Pyrrha was a very skilled fighter in RWBY. They both have a strong sense of honor. Reinhardt could teach Pyrrha some of his combat techniques from the Overwatch world, and Pyrrha could show Reinhardt some of the unique fighting styles in RWBY. Also, Widowmaker and Weiss could be an unexpected but fascinating pairing. Widowmaker's cold - blooded assassin nature could contrast with Weiss' more noble upbringing, and they could learn from each other in terms of combat and strategy.
Some fanfictions focus on a character - swap scenario. Imagine Ruby being in the body of Tracer and having to deal with the fast - paced, high - tech world of Overwatch while still having her own personality and some of her RWBY powers. Or Winston being in the body of a Beowolf and trying to figure out how to control the Grimm form while also using his own intelligence. This creates a really interesting dynamic as the characters have to adapt to new bodies and new environments.
One idea could be the Overwatch heroes being transported to the RWBY world. They could team up with Team RWBY to fight a new common enemy, like a powerful Grimm that is immune to normal attacks but vulnerable to Overwatch tech. Another plot could involve a character exchange, where a RWBY character like Ruby goes to the Overwatch world and learns about their technology and fighting styles, and then brings back new knowledge to her own world.
To start an Overwatch crossover fanfic, you should begin by getting really familiar with both Overwatch and the other universe you're crossing it with. If it's a crossover with the DC Universe, study the powers, personalities, and backstories of the characters from both. Then, come up with a conflict that would require both sets of characters to work together or against each other. For instance, a powerful villain from DC has stolen some crucial technology from Overwatch. Outline your story, including the main events, character arcs, and how the crossover will end. Don't forget to give your story a unique title that reflects the crossover.
I think Mercy and Ruby would make an interesting pairing. Mercy is a healer in Overwatch and Ruby is the leader of Team RWBY. Ruby could learn about Mercy's advanced medical technology and how she uses it in combat. Meanwhile, Mercy could be inspired by Ruby's determination and leadership. Another great pairing could be Winston and Yang. Winston is a brilliant scientist and a powerful fighter as a gorilla. Yang is a brawler with a lot of strength. They could have some epic sparring sessions and also exchange knowledge about strength - based fighting and scientific inventions.
One interesting idea could be an Overwatch crossover with the world of Harry Potter. For example, Tracer could be a student at Hogwarts, using her time - traveling abilities in magical ways within the school. Another idea is a crossover with the Star Wars universe. Maybe Reinhardt as a Jedi, with his rocket hammer being a unique lightsaber - like weapon. And a crossover with the Lord of the Rings, where Orisa could be a guardian of a certain part of Middle - earth, protecting it from the forces of evil with her shield and gun.
Another possibility is that there's a rift in time or space that brings the two universes together. The TF2 and Overwatch characters find themselves in a strange new world that's a mix of both of their own. They have to figure out how to get back to their respective universes while also dealing with local threats. Some characters might be tempted by the different cultures and powers they encounter, which could cause internal conflicts within the combined group.
Reinhardt and Yang would be an interesting pair. Reinhardt is an old - fashioned knight, full of honor and valor. Yang is a tough fighter with a bit of a hot - tempered side. They would likely start off butting heads as their personalities are quite different. But as they train together or face a common enemy, they would come to respect each other. Yang could learn about the code of chivalry from Reinhardt, and Reinhardt would be impressed by Yang's raw strength and her ability to keep fighting even when outnumbered.
Another interesting concept could be a character swap. Imagine Tracer from Overwatch in the Halo universe, using her time - jumping abilities in the middle of a large - scale Halo battle. Or a Spartan in the Overwatch world, trying to adapt to the more urban and team - based combat scenarios there.