First, give the MC a clear backstory. For example, if they are a human, explain where they come from, their family, and what led them to get involved with the events related to Cell. Maybe they were training in martial arts because they had a personal vendetta against powerful beings after their family was killed by a random villain. This would give them a motivation to face Cell.
Secondly, give the MC some unique abilities or traits. It doesn't have to be super - powerful at first. It could be something like an extremely high IQ that allows them to analyze Cell's fighting patterns quickly. This would make them stand out and be more believable as a character who can hold their own against Cell in the fanfic. They could use their intelligence to develop new strategies or even find weaknesses in Cell that the other Z - fighters haven't noticed yet.
One idea could be that the MC is a scientist who was involved in Cell's creation and now has to face the consequences. Maybe they try to find a way to stop Cell's rampage by using their knowledge of his genetic makeup.
One possible fanfic could be about Goku's intense training before the Cell Games. He might be shown pushing his limits in the Hyperbolic Time Chamber, trying out new techniques and forms to defeat Cell. Maybe he discovers a new power level that no one, including himself, expected.
A common theme is power. Since Cell is a powerful character in DBZ, often in 'cell x oc dbz fanfic', the OC might be on a journey to gain power or deal with Cell's power. Another theme is redemption. Sometimes the fanfic might explore Cell's character in a way that gives him a chance at redemption through his relationship with the OC.
Well, one way to find good 'cell x oc dbz fanfic' is to check out popular fanfic websites like FanFiction.net or Archive of Our Own. Just search for the 'cell x oc dbz' tag and browse through the results. Some might have really interesting takes on the relationship between Cell and an original character in the Dragon Ball Z universe.
First, give the OC a unique power. For example, the ability to manipulate energy in a way that no one in the DBZ universe has seen before. Second, give them a distinct backstory. Maybe they come from a long - lost race that was wiped out by Frieza's ancestors. And third, give them a unique personality. Instead of being the typical heroic type, make them morally grey. They might be willing to team up with Cell if it means achieving their own goals.
The concept of 'cell drain tail' in dbz fanfic might bring together some interesting elements. The tail, being a unique part of Saiyan biology, could be the target or source of the cell drain. It could be that the cell drain is a result of some new form of bio - engineering or alien technology. There might be a focus on the physical and emotional changes the characters go through. For example, if a Saiyan's tail is being drained at the cellular level, it could cause them pain, weakness, or even strange mutations. And this could lead to new story arcs where the character has to find a way to reverse the process or use it to their advantage in some way.
There are so many Dragon Ball Z fanfics that it's hard to point out ones related to 'cell drain tail' right away. One way to find them could be to join some Dragon Ball Z fan groups on social media platforms. There, fans often share and discuss interesting fanfics. Maybe someone has come across a story with this specific theme.
One possible plot could be that the mc (main character) discovers a strange cell that has some sort of connection to a powerful db (database). Maybe this cell holds the key to unlocking some hidden knowledge or power within the database. The mc then has to go on a journey to figure out how to access and use this knowledge or power without falling into the wrong hands.
If Goku and Female Cell interacted, it could change the perception of enemies in the DBZ universe. Their cooperation might lead other fighters to be more open to the idea of redeeming former foes. For example, if they manage to work together successfully, Vegeta might rethink his stance on some of the villains he's faced.
A great plot point could be Goku teaming up with an unexpected ally during the Cell Games. For example, an old enemy who realizes that Cell is a greater threat. They could combine their powers in a unique way to take on Cell.