Luke Skywalker could be another key character. Since he is Vader's son, his presence could add an interesting dynamic. He might be the one who somehow triggers the battle between Anakin and Vader, or he could be in a position to influence the outcome of their fight, perhaps by appealing to the remaining good in Anakin or by facing off against Vader himself in a three - way struggle.
Darth Revan might see Anakin as a powerful tool. He could try to manipulate Anakin further towards the dark side, using his own experiences of falling to the dark side to tempt Anakin. Maybe he would offer Anakin power beyond his wildest dreams if he fully embraced the dark side.
It really depends on how you write it. If it's Anakin at his peak before turning to the dark side, he has a lot of raw power and potential. But Vader has years of experience as a Sith Lord. So, it could go either way.
One idea could be a story that focuses on Anakin's internal struggle between his love for Padme and his fall to the dark side as Darth Vader, while Luke and Leia unknowingly grow up in the shadow of their father's actions. It could explore how their lives might have been different if Anakin had not turned, and how they eventually come to terms with his true identity.
In such a fanfiction, one possibility is that Anakin Skywalker might initially be in shock upon seeing Darth Vader. He could struggle to come to terms with what he has become. Maybe there would be a battle of wills as Anakin tries to fight against the dark side within Vader.
A possible plot is a fanfic where Anakin, in his Darth Vader form, has a vision of a different future where he didn't lose Padme. This vision makes him question his loyalty to the dark side. Meanwhile, Luke and Leia are on a mission to rescue their father from the clutches of the Emperor. The story could be filled with emotional reunions and battles between the light and dark forces.
One common theme is redemption. Many fanfics explore the idea of Darth Vader still having a glimmer of Anakin inside and the possibility of his return to the light side. Another theme is the struggle with the dark side. Writers often depict Anakin's internal conflict as he fully embraces the power of Darth Vader. There's also the theme of lost love, especially his relationship with Padmé and how it affects him as Darth Vader.
Well, Anakin Skywalker's journey to becoming Darth Vader was a complex one. He was a slave on Tatooine as a child, and his strong Force abilities were noticed early. He was taken under the wing of the Jedi. But his mother's death, his love for Padmé, and the political intrigue in the galaxy all played a part. The Jedi's distrust of him and Palpatine's insidious influence pushed him over the edge. He believed that the dark side could give him the power to prevent the loss of those he loved, so he embraced it, thus becoming Darth Vader.
One idea could be a what - if scenario where Anakin in his pre - Vader state somehow gets a glimpse of his future as Vader. He could then fight against the dark side within himself that would turn him into Vader. Another could be a time - travel plot where Vader is sent back to face Anakin, and Anakin has to decide whether to accept his possible future or fight against it.