In a fanfiction, it could be interesting to see a scenario where Megatron and Optimus Prime are reborn in a different time and place, perhaps in a peaceful Cybertron that has long forgotten the war. They might struggle to adapt to this new world where their old identities as war leaders are no longer relevant. Their journey could involve rediscovering themselves and learning to live in harmony, which would be a huge departure from their traditional roles.
One common theme is self - discovery. The OCs often have to figure out who they are and what their place is in the Cybertronian world. For example, they might discover hidden powers or a new purpose in the midst of the war.
Perhaps a story where Jack discovers a hidden power within himself that has a connection to Cybertronian technology. This power could make him a key figure in a conflict between the Autobots and Decepticons. He might have to learn to control it with the help of his Cybertronian friends.
A rogue Cybertronian who has his own agenda and doesn't care about the Autobot - Decepticon conflict. This character could see Jack as an easy target or a means to an end, like stealing some valuable Earth technology that Jack has knowledge of.
Maybe it could be about Harry Potter being reborn as a Cybertronian baby and having to adapt to the unique culture and abilities of the Cybertronians. He might discover he has some special powers related to both his wizarding past and his new Cybertronian form.
One plot idea could be that the Cybertronian reader is a healer. Predaking gets seriously injured in a battle, and the reader is the only one willing to help him. As the reader nurses Predaking back to health, they form an unexpected bond that challenges the social norms of Cybertron.
In this fanfiction, the relationship between Predaking and the Cybertronian reader could be complex. The reader might be on a mission to study Predaking, trying to understand his nature. This could lead to some tense moments as Predaking is not one to be easily studied. However, through their interactions, a mutual respect could develop, changing the course of the story.
One great Transformers OC Cybertronian fanfiction is 'The Lost Spark'. It follows an original character as they navigate the complex politics and battles on Cybertron. The story has really well - developed characters and an engaging plot.
One common theme is adventure. They might go on missions together across Cybertron or other planets. Another theme is sacrifice, where either Optimus or the reader character might be put in a situation where they have to sacrifice something for the greater good.
Megatron could also be a major character. Maybe he views Harry Potter as a threat to his power and plans. He could try to either destroy Harry or use his unique abilities for his own evil purposes. And then there could be Bumblebee, who befriends Harry and helps him communicate with the other Autobots, since Bumblebee is often good at making connections.