For some fans, it's about exploring different aspects of the Transformers universe in a more 'out - there' way. MPreg in general is a very niche and interesting concept in fanfiction, and when applied to these well - known characters, it can create stories that are both thought - provoking and entertaining. It's a way to break the boundaries of the traditional narrative and see what kind of new stories can be told.
It can also be appealing from a creative writing perspective. Writers can play with the personalities of the characters in this new and strange scenario. For example, how would Optimus Prime react to Megatron being in such a state? And vice versa. It gives a whole new layer to their complex relationship.
You can try looking on some fanfiction websites like Archive of Our Own (AO3). It has a large collection of Transformers fanfictions, and there might be some related to Optimus Prime and Megatron in the MPreg genre.
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.
In a fanfic about Optimus Prime x Megatron, their relationship could be explored in a more philosophical way. For example, they might debate the nature of good and evil, power and responsibility. Optimus believes in protecting all life, while Megatron has his own ideas about power and how it should be used. This kind of fanfic could show how their different viewpoints could either bring them closer together or drive them further apart.
A great angle for a Megatron x Optimus Prime fanfic could be a body - swap situation. They are forced to inhabit each other's bodies due to some alien technology gone wrong. This leads to them having to understand each other's perspectives on a whole new level. They start to see the reasons behind their actions in the past and develop a new - found respect for one another.
One possible fanfiction could be about Optimus Prime and Megatron having to team up against a greater threat. Maybe an ancient evil from Cybertron's past resurfaces that is so powerful that their usual enmity has to be put aside. They start off distrusting each other but as they face battles together, they gradually come to respect the other's fighting skills.
The plot could be about a power struggle. Megatron wants total control over Cybertron, but Optimus Prime stands in his way. However, instead of just fighting, there are political intrigues involved. There could be other characters influencing their decisions. Maybe some Autobots who think Optimus is being too soft on Megatron, and some Decepticons who think Megatron is being too cautious.
If they switched sides in fanfiction, it would be a huge shock. Optimus as a 'bad guy' would be very different. He might use his leadership skills in a more tyrannical way. Megatron as a 'good guy' would be strange too. He'd have to fight his own nature of seeking power. But it could make for an interesting story as they both struggle with their new identities.
In a fanfiction where they unite, it could start with a common threat that neither side can face alone. For example, an alien race invades Cybertron. Megatron and Optimus Prime realize that their brotherly bond is stronger than their differences. Together, they could form a new strategy, using both Autobot and Decepticon forces in a coordinated way to repel the invaders.
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.
A really cool fanfiction I read had Female Optimus Prime and Megatron in an alternate reality. They were both outcasts in their own worlds. They formed an unlikely alliance and the story focused on their journey together. It was full of action and also some really sweet moments where they showed that they cared about each other's well - being, despite their past enmity.