One idea could be to explore the backstories of the minor characters in the Gears of War universe. For example, you could write about how a particular soldier got recruited into the COG. Another idea is to create an alternate timeline where the Locust invasion happened differently. Maybe the COG discovers a new weapon early on and changes the course of the war. You could also focus on the relationships between the characters outside of combat, like how they unwind and deal with the stress of the war.
A great concept for a Gears of War fanfic is to set it in a post - war scenario. Show how the survivors are rebuilding society. Are there still remnants of the Locust threat? How do the different factions interact now? Or you could do a fanfic centered around a new recruit who has to quickly adapt to the brutal world of Gears of War. They could face challenges not only from the enemy but also from within their own ranks due to their inexperience.
One interesting idea could be exploring the backstories of the minor characters. For example, the life of a regular Gear soldier before the war, how they were recruited, and their families. Another idea is to create an alternate universe where the Locust and humans form an alliance against a new common enemy. It could change the whole dynamic of the Gears of War world.
For Gears of War 4 crossover fanfiction, a crossover with the Star Wars universe would be really exciting. The Gears' tough and gritty combat style against the backdrop of the Star Wars galaxy. The Jedis and Siths could interact with the Gears in various ways. Maybe the Gears would get involved in a conflict between the Galactic Republic and the Separatists, using their own brand of weaponry and tactics.
A cool concept for a Gears of War self - insert fanfiction would be if you were a member of an ancient civilization that has some hidden knowledge about the Locusts. You get rediscovered during the war and use your knowledge to turn the tide. You could also be in a relationship with one of the main characters, like Marcus Fenix, and through that relationship, influence the events of the war in unexpected ways.
Well, you could have an OC that is a former athlete turned soldier. Their physical abilities could give them an edge in combat, but they also have to deal with the mental toll of the war. They might befriend an old - timer in the Gears of War who teaches them the ropes. Or an OC who is a journalist embedded with the Gears. Their job is to report the truth, but they get caught up in the middle of a conspiracy within the military ranks, and they have to use their wits and the help of their newfound friends in the Gears to expose it.
One idea could be to have the Swarm characters interact with the Gears of War protagonists in a post - apocalyptic city. They could form an uneasy alliance to fight a new, even greater threat. For example, a powerful new enemy that is immune to the weapons they currently have.
Well, a great plot for Gears of War Berserker fanfiction could involve a group of soldiers who discover a young Berserker that seems to have some level of intelligence. They try to train it or at least understand it. Another could be set in a post - apocalyptic world where the Berserkers have evolved further and the main character has to figure out their new abilities to survive. And, a third option is a story about a scientist who was involved in creating the Berserkers and now has to face the consequences when one gets loose in his lab.
One idea could be exploring the origin of the Locust in more depth. Maybe there was a scientific experiment gone wrong that led to their creation. Another could be a story where a human and a Locust form an unlikely alliance to fight a common, greater threat within the Gears of War universe.
One idea could be to have the Spartans from Halo team up with the COG soldiers from Gears of War to fight a common enemy like a new alien race that combines the threats of the Covenant and the Locust. They could exchange combat techniques and weaponry, leading to some epic battles.
One idea could be to have the characters from Gears face the same kind of epic battles as in God of War. For example, the COG soldiers could find themselves in a world full of Greek mythology elements. Maybe they have to fight alongside Kratos against some new, powerful monsters that are a mix of the grotesque creatures from Gears and the mythological beasts from God of War.
A plot idea could involve Kait forming an unlikely alliance. For example, she teams up with a former enemy who has some unique knowledge or ability. This alliance could lead to a series of adventures as they try to stop a new, powerful enemy. Also, a story about Kait's inner struggle with the dark secrets she's uncovered would be engaging. She could be torn between using the knowledge for good or being corrupted by it.