Well, one interesting concept could be unique character designs for the self - inserted original characters. They might have special powers or abilities that are different from the regular Dragon Ball Z characters.
There are fanfictions where the Si Oc is a Saiyan from a different planet than Vegeta and Goku. This Oc might have been sent away as a baby just like Goku but ended up on a completely different world. When they return to the Dragon Ball Z universe, they have a different fighting style and set of values. They could form alliances with the Z - fighters in a very different way, perhaps being more cautious or more aggressive, depending on their experiences on the other planet.
First, know the Dragon Ball Z universe well. Understand the powers, the races, and the existing storylines. This knowledge will help you create a believable SI OC. For example, if your OC has a power that's too overpowered without any explanation, it won't fit well.
One way to create a Frieza Race OC for Dragon Ball Z fanfiction is to first think about their physical appearance. They could have the signature purple skin, white horns, and long tails like Frieza. For their personality, maybe they're more cunning and strategic than the average Frieza Race member. They could be an outcast who doesn't agree with the cruel ways of their race and is secretly trying to find a way to change their people's nature. Their power level could start off relatively low but through various adventures in your fanfiction, they grow stronger and learn new techniques.
First, think about your Oc's backstory. Decide where they come from, what their family is like, and what their motivation is. For example, if they are a Saiyan, why are they different from the others? Then, consider how they will fit into the existing Dragon Ball Z universe. Will they befriend Goku? Or be an enemy of Vegeta? You can start with a simple idea like that.
Common themes in 'Dragon Ball Z Human OC Fanfiction' include heroism. The human OCs usually end up being heroes in some way, whether it's saving a city or the whole universe. Another theme is the exploration of new powers. These OCs might discover powers that no one else in the Dragon Ball Z world has. And the theme of family also shows up sometimes. They could be searching for their lost family or creating a new family - like bond with the other characters.
There are 'Dragon Ball Z OC Fanfiction' where the OC is a non - Saiyan but has a special connection to the Dragon Balls. For example, an OC who is a wizard from a far - off planet. This wizard could use magic in ways that blend with the ki - based combat of Dragon Ball Z. They might be on a quest to protect the Dragon Balls from an evil force that wants to misuse their power for world domination.
One interesting 'Dragon Ball Z OC' fanfiction story could be about an OC who has a unique power that they discover during a battle against a new enemy. For example, an OC might have the power to manipulate time in a very limited way, like slowing down an opponent's attack just enough to dodge. Another could be an OC that is from a different planet but has a connection to the Saiyans. This OC could bring new knowledge about Saiyan history or abilities that were previously unknown.
Power - up is a very common theme. Since Saiyans are known for their strength, in OC fanfiction, they often go through various power - up stages. Another common theme is identity. OC Saiyans usually have to figure out their place in the Dragon Ball Z universe, whether they are related to the main Saiyan characters or are on their own path.
Potential allies for an OC in 'Dragon Ball Z OC Rebirth Fanfiction' could include Android 18. She has her own sense of justice and could team up with an OC for a common cause. Yamcha might also be an ally. He has a lot of experience in fighting and could share some useful combat tips. The Kaioshin of Time, Chronoa, could be an interesting ally. She has the power to manipulate time and could help an OC in situations where time - related powers are needed. Additionally, the Galactic Patrol could see an OC as a valuable addition to their team in protecting the galaxy and offer their resources and protection.