Another great storyline is a time - travel one. Optimus Prime and Megatron are sent back in time to the early days of Cybertron before the war. They see how their actions in the present have been influenced by the events of the past. They must work together to prevent certain events from occurring that led to the great war, all while dealing with their own differences in ideology.
One possible storyline could be a redemption arc for Megatron. In this fanfiction, Megatron, after countless battles with Optimus Prime, begins to question his motives. He realizes the destruction he has caused and tries to make amends. Optimus, initially skeptical, gradually sees the change in Megatron and they form an uneasy alliance to face a greater threat that endangers both Autobots and Decepticons alike.
One possible storyline could be them facing a powerful new Decepticon threat together. Optimus and Arcee would have to combine their skills, with Optimus using his strategic mind and Arcee her speed and agility. Another could be a story set in a post - war scenario where they are trying to rebuild Cybertron and their relationship deepens during the process. And perhaps a time - travel plot where they go back in time and have to change an event that will save Cybertron in the future.
One great storyline could be a story where Megatron and Optimus Prime are forced to team up against a greater threat from another universe. They have to put aside their differences and learn to trust each other. Another could be a pre - war story, exploring their relationship before they became enemies, perhaps they were once friends or comrades. A third could be a story where they are both stranded on a strange planet and have to rely on each other's unique abilities to survive and find a way back home.
Perhaps there's a story where Optimus and Megatron are both stranded on a desolate planet. Without their armies and with limited resources, they have to rely on each other to survive. As they struggle to find a way off the planet, they start to understand each other better. Megatron realizes that Optimus isn't just a naive idealist and Optimus sees that Megatron has reasons for his actions that are more complex than just pure evil.
Secondly, create a unique setting. Instead of the usual battle - torn Cybertron, set the story in a parallel universe where the Autobots and Decepticons have different roles or in a post - apocalyptic Cybertron where they have to rebuild together. This can add a fresh perspective to their relationship.
It could be developed by exploring their past. Maybe there was an event in their youth that they both remember differently. As they start to talk about it in the fanfic, they begin to see each other in a new light. For instance, they might have once been friends or at least comrades in a fight against a common enemy before their ideologies split them apart. This exploration of the past can build a more complex relationship between them.
One interesting storyline could be a story where Megatron is injured in battle and Optimus Prime, against all odds, decides to take him in and nurse him back to health. During this time, they start to see each other in a different light and develop an unexpected bond.
Fanfiction about them can explore different universes and scenarios. For example, what if they were raised together? How would their relationship be different? It gives fans a chance to play with the established lore and create new and exciting stories that the official Transformers storylines may not explore. It also allows for deeper exploration of their motives and personalities.
Another could be a story set in a post - war scenario. Optimus Prime is trying to rebuild Cybertron, and Ratchet is right there with him. They encounter various challenges like lack of resources and dissent among the remaining Cybertronians. Their friendship is strained but ultimately grows stronger as they work through these problems.
Perhaps a fanfiction where a powerful artifact is discovered that has the potential to change the balance of power on Cybertron. Megatron wants it for his own gain, and Optimus Prime wants to protect it. But when they both touch it simultaneously, they are transported to an alternate dimension where they must work together to find a way back, all while learning more about each other than they ever thought possible.
There could be a fanfiction where a strange energy source affects Optimus Prime and Megatron, causing them to swap personalities or abilities. This would be a humorous yet also thought - provoking plot. They would have to navigate their new selves while still trying to lead their factions. The Autobots would be confused by an aggressive Optimus and the Decepticons would be equally bewildered by a more pacifist Megatron.