One idea could be an OC Decepticon who has a unique ability like being able to control electricity. The plot could revolve around this OC trying to prove their worth to Megatron by taking on difficult Autobot missions. For example, they target an Autobot outpost that holds a powerful energy source. The OC's journey to the outpost, facing Autobot defenses and internal Decepticon rivalries along the way, would make for an exciting story.
A plot could be about an OC Decepticon who discovers a hidden Autobot plan to build a super - weapon. This OC, instead of immediately reporting it, decides to use this information for their own gain. They start making deals with both sides secretly. As the story progresses, they get in deeper and deeper trouble as both the Autobots and Decepticons start to suspect their true motives.
Perhaps an OC Decepticon who was once an Autobot. They could have been betrayed by the Autobots and joined the Decepticons out of revenge. The fanfiction could explore their inner struggle between their former Autobot values and their new Decepticon allegiances while they participate in battles against their former comrades.
First, think about their abilities. For example, if they can fly, how does that impact their role in battles or in the Decepticon hierarchy? Second, consider their backstory. Maybe they were once an Autobot who was betrayed and turned to the Decepticons. Their personality is also crucial. Are they cruel like most Decepticons or do they have a softer side? For instance, they could be cruel to their enemies but protective of their fellow Decepticons.
One possible fanfiction could be about a Decepticon OC named Blaze. Blaze was a young Decepticon who was always overlooked by Megatron. He had the unique ability to manipulate fire, but his small stature made others underestimate him. One day, during a battle with the Autobots, Blaze found an opportunity to prove himself. He used his fire powers to create a diversion, allowing the Decepticons to gain an upper hand. However, he soon realized that the Decepticon cause might not be as noble as he once thought.
A plotline could be that a human hacker manages to infiltrate the Decepticon communication network. This gives the Autobots an edge, but also makes the human a prime target for the Decepticons. They send their best agents to hunt down the human, leading to a cat - and - mouse chase across the Transformers Prime landscape.
One idea could be an OC who is a medic that gets captured by Megatron. Megatron initially sees the OC as a tool to use against the Autobots but gradually develops an odd respect for the OC's skills and tenacity. Another plot could involve an OC who has a special power that Megatron wants to harness for his own evil plans. As he tries to manipulate the OC, the OC starts to see through his lies and tries to turn the tables on him. A third plot might be an OC from a different dimension who accidentally lands in the Transformers Prime universe and catches Megatron's attention. He's intrigued by this strange new being and tries to either recruit or destroy the OC.
One idea could be an OC human who discovers a hidden power within themselves that can interact with the Cybertronian technology in unique ways. For example, they might be able to heal damaged Transformers using a strange energy they possess. Another plot could involve an OC human getting caught in the middle of a battle between the Autobots and Decepticons and having to use their wits and new - found friendships with the Autobots to survive and help them. A third idea is an OC human who is a mechanic and accidentally creates a new device that attracts the attention of both Autobots and Decepticons, leading to a series of adventures as they try to keep it out of the wrong hands.
The OC could be from another planet that has a connection to Cybertron. Jack and the OC meet when she is looking for something on Earth related to her home planet. They start off as strangers but gradually fall in love as they discover more about each other's worlds.
To create a believable OC Decepticon, start with their motivation. What drives them to be on the Decepticon side? It could be a thirst for power or a desire to see the Decepticons rule Cybertron. Next, develop their relationships with other known Decepticons. Do they respect Megatron unconditionally or are they secretly planning to overthrow him? Their interactions with characters like Starscream can add depth. And don't forget about their flaws. Maybe they are overconfident in their abilities, which often leads them into dangerous situations.
In a Transformers Prime fanfiction, a human could befriend a Decepticon who is disillusioned with the evil ways of their faction. Together, they try to find a way to bring peace between the Autobots and Decepticons. This would involve many challenges as both sides are distrustful of the other. The human's unique perspective might be the key to making it all work.
One idea could be a story where Optimus Prime has to team up with an unlikely ally from another planet. Maybe a small, scrappy alien that has some unique abilities that can help in the fight against the Decepticons. This would add an interesting dynamic as Optimus has to learn to work with a very different being.
A plot idea could be that Optimus Prime time - travels. He goes back to the beginning of the war between the Autobots and the Decepticons and tries to prevent it from starting. Along the way, he meets younger versions of his friends and enemies and has to deal with the consequences of changing the past. Or perhaps, Optimus is trapped in a dimension where the laws of physics are different. He has to adapt quickly and find a way back to his own world while also facing off against new threats.