Another idea is a story where the Covenant from Halo discovers the Force in the Star Wars universe. They might see it as a new form of 'holy' power and try to either harness it or destroy those who possess it. This could lead to some epic battles between the Covenant and the Jedi or Sith.
Some interesting concepts in Star Wars Halo crossover fanfic include the use of Halo's advanced weaponry in the Star Wars universe. Picture a Stormtrooper wielding a Spartan Laser. The reverse is also interesting, like a Spartan using a lightsaber. Then there's the potential for political intrigue. How would the Galactic Empire and the UNSC interact? Would they be allies or enemies? And what about the role of the droids and AI in both universes? Could Cortana and R2 - D2 work together?
One idea could be that the Spartans from Halo are sent through a wormhole and end up in the Star Wars galaxy. They could then get involved in the Clone Wars, with their advanced technology and combat skills being a huge asset or a source of great confusion among the different factions. Maybe they team up with the Jedi at first, but then some misunderstandings occur due to their different ways of handling situations.
A great plot could be that Master Chief somehow gets transported to the Star Wars universe. He could find himself in the middle of a battle between the Sith and the Jedi. His combat skills and advanced armor would be a huge asset to either side. Or perhaps there could be a story where the Forerunners have some ancient connection to the Force in the Star Wars galaxy. This could lead to a search for lost Forerunner technology that could change the balance of power in the Star Wars universe.
One idea could be to cross Halo Wars with another popular sci - fi franchise like Star Trek. Imagine the Covenant and the Federation having to deal with each other. Another idea is to have a crossover with a fantasy world, like Lord of the Rings. Maybe the Spartans end up in Middle - earth fighting alongside the elves and dwarves against a new threat that has elements of the Flood. A third idea could be a crossover with a post - apocalyptic world. The Halo Wars units could be trying to survive in a world full of mutants and scarce resources.
One interesting idea could be the technology exchange. For example, the Star Trek's warp drive might be compared or even combined with the Star Wars' hyperdrive in some creative ways. Another could be the meeting of characters. Imagine Captain Kirk facing off against Darth Vader. It would be a clash of two very different leadership styles and moral compasses.
Well, you could create a story where the Naruto characters are in the Star Wars universe. Picture Naruto as a Jedi in training, learning the ways of the lightsaber and the Force from the likes of Luke Skywalker. Or perhaps Sasuke could be a Sith apprentice, his Sharingan abilities adding a new dimension to Sith powers. And Hinata could be a Jedi healer, using her Byakugan to sense injuries in a different way.
Well, a cool concept would be for Luke Skywalker to end up in the Marvel universe and train some of the young superheroes in the ways of the Force. Or perhaps the X - Men could find themselves in a conflict in the Star Wars galaxy, with their mutant abilities adding a new dynamic to the Star Wars battles.
One idea could be a crossover with the original Star Wars trilogy characters. Maybe the Rebels crew teams up with Luke Skywalker and Han Solo to take on a new, powerful Sith threat. This would bring together the scrappy underdog feel of the Rebels with the classic heroism of the original trilogy.
One idea could be a crossover where a Halo Terran character gets transported to the Star Wars universe. They might bring their unique combat skills and technology, creating an interesting dynamic with the Jedi and Sith. For example, a Terran Spartan could find themselves in the middle of a battle between the Rebels and the Empire, and their advanced armor and weaponry could turn the tide of the battle in unexpected ways.
One idea could be a crossover where Master Chief from Halo ends up in the Star Wars universe and has to team up with the Rebel Alliance against the Empire. He could introduce his advanced combat skills and technology to the Rebels.