Explore their different ideologies. Luke believes in the light side and redemption, while Vader is deep in the dark side. Have them debate their beliefs in a way that shows respect for each other's views. Maybe Luke tries to convince Vader that there is still good in him, and Vader challenges Luke's naivete about the power of the dark side. This back - and - forth can build a complex relationship.
Believability in their relationship also depends on how you handle the power dynamics. Darth Vader is extremely powerful in the Force and has a high rank in the Empire. The OC might be initially intimidated but then find ways to hold their own. This could be through their own unique skills or knowledge. For example, if the OC is an expert in ancient Sith artifacts and Vader needs their help, it gives them a certain leverage. As they interact more, this power dynamic can shift and change, creating a more nuanced and believable relationship.
One idea could be a story where Darth Vader secretly trains Luke in the ways of the Force before Luke fully realizes who he is. This would add an interesting layer of secrecy and moral conflict for Vader.
One idea could be a story where Luke discovers a way to temporarily reverse Vader's Sith corruption, leading to some heart - to - heart conversations between them as Anakin. Another could be a fanfic where they have to team up against a new, greater threat in the galaxy that neither the Rebels nor the Empire can handle alone. Maybe a story where Luke gets trapped in a Sith - created alternate dimension and Vader has to go in and rescue him to atone for his sins.
A young, Force - sensitive alien who has the power to manipulate time could be an interesting addition. This character could bring a new dynamic to the relationship between Luke and Vader. For example, they might have to protect this alien from the Empire or the Sith who want to use its power for evil.
Their relationship can be developed through flashbacks. For example, showing memories of Anakin and Ahsoka's time as master and apprentice, and then contrasting it with their current hostile stances as Ahsoka and Darth Vader. This can add depth to their interactions.
Their relationship could develop uniquely if Darth Vader starts to have dreams about Baby Luke's future as a great Jedi. These dreams make him question his loyalty to the dark side. So he begins to secretly guide Luke in the ways of the Force, like leaving behind ancient Jedi texts for the baby to find when he's older.
To create a believable character, think about their motivation. If you're in a world with Darth Vader, your character might be motivated by a desire to gain Vader's approval and rise in the Sith ranks. Also, consider their personality. Are they more calculating like Vader or impulsive? Their interactions with other characters, especially Vader, should be based on these aspects. For example, if your character is impulsive, they might often act without thinking, which could either annoy or amuse Vader, depending on the situation.
The relationship could start with the female stormtrooper showing great combat skills that catch Darth Vader's attention. He then begins to give her more difficult tasks, and in the process, they develop a mutual respect. For example, she could be the only one in her unit to survive an ambush, and Vader sees her determination.
In fanfiction, their relationship could develop more quickly towards mutual understanding. Maybe Luke could convince Vader to turn away from the dark side much earlier, and they could start training together as Jedi. This would be a huge shift from the original story.
To create a believable relationship, start with mutual respect. For example, Danny respects Vivalandra's powers and knowledge from her world, and she respects his skills as a ghost - fighting hero. They can exchange stories about their respective worlds, which helps them understand each other better.