A really exciting plotline might involve Ahsoka getting trapped in Vader's memories. She has to navigate through his past, seeing his fall to the dark side and his relationship with Anakin Skywalker. This could lead to some very emotional and thought - provoking moments as she tries to understand him better and perhaps find a way to save him.
In a fanfiction, Darth Vader might finally face his past with Ahsoka. Maybe he would have moments of hesitation in their battles, as memories of their time as master and apprentice resurface. This could lead to an internal struggle within Vader, torn between the Dark Side and his former self.
In fanfiction, their duel could be more about psychological warfare. Ahsoka might use her knowledge of Anakin to try and get into Vader's head, making him question his loyalty to the dark side. For example, she could bring up memories of their time as master and apprentice. This would add a layer of complexity not always seen in the official duels.
One scenario could be that Darth Vader discovers Ahsoka is still alive and is conflicted between his Sith loyalty and his past connection with her. He might secretly try to protect her from other threats in the Empire without revealing his identity.
Their relationship could be shown as very conflicted. Darth Vader is deep in the Dark Side, but Ahsoka still remembers the good in Anakin. She might be angry at what he has become, while also feeling a sense of pity. Vader, on the other hand, might see her as a reminder of his failure as a Jedi.
One way to further explore their relationship is through the Force. Since they are both strong in the Force, they could sense each other's emotions and intentions from a distance. For example, Vader might feel Ahsoka's determination to stop him, and it could remind him of her as a young Padawan. Also, a story could be written where they communicate through the Force without actually meeting, sharing memories and feelings about their past together.
Well, a cool plot might be that Ahsoka gets trapped in a Sith - created illusion world by Vader. In this world, she has to face her past traumas and fears related to Anakin's fall. Meanwhile, Vader is conflicted as he watches her struggle, memories of his past with Ahsoka resurfacing. Or there could be a story where they both are on a mission to retrieve a powerful Jedi/Sith artifact, and their paths cross in a race against time.
There's a fanfic titled 'Vader's Redemption'. In this story, Vader starts to question his loyalty to the Emperor much sooner, especially after some profound encounters with Luke. It's a great read as it shows the internal struggle of Vader while also exploring the bond between father and son in a new light. It's full of action-packed scenes and deep emotional moments.
He might be shocked by the advanced technology. The Empire's weaponry would seem primitive compared to future tech. He could also be intrigued by the new forms of the Force if they had evolved.
One of the most dramatic encounters could be their lightsaber duel. The contrast between Ahsoka's acrobatic and precise style and Vader's brute force is intense. Their duel is not just about physical combat but also about the ideological clash between the Jedi and Sith. Ahsoka represents the hope and the Jedi way that Vader once knew and discarded. Another aspect could be the moments of silent confrontation, where their expressions and the Force around them create a palpable tension.