Well, in fanfiction, when Darth Vader meets Yoda, it could lead to a battle of ideologies. Vader, having turned to the dark side, represents power and control through the Sith ways. Yoda stands for the Jedi's connection with the Force in a more harmonious and selfless way. They could engage in a Force - powered duel where Vader tries to overpower Yoda with his dark side strength, but Yoda uses his wisdom and experience to counter.
Perhaps Vader would start with 'You cannot stop me, old one.' Yoda would then calmly say 'Not so, young Skywalker. The Force is with me.' This shows the contrast between Vader's arrogance in the dark side and Yoda's confidence in the light side of the Force. There could also be a moment where Vader asks Yoda why he should return to the light, and Yoda gives a long speech about the true nature of the Force and how the dark side is a path to self - destruction.
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.
In such a fanfic, the Avengers' diverse powers would clash with Darth Vader's formidable Force abilities. Iron Man could use his high - tech suits to try and outmaneuver Vader's lightsaber attacks. Captain America might lead the charge with his shield against Vader's dark side - enhanced combat skills. It would be an epic battle of good from different universes against Vader's Sith - influenced evil.
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.
Darth Yoda might have a more menacing look. His eyes could be a glowing red instead of their usual color, symbolizing his turn to the dark side. His robes might be darker, perhaps black with red accents.
Darth Vader could encounter advanced droids that have developed personalities and even some form of Force - like abilities in this future. These droids might be a new challenge for him as they are not like the droids he is used to dealing with in his own time. He may also meet future versions of his former allies or enemies, who have been reincarnated or cloned in some strange new way, with different personalities but still with a connection to their past selves.
In the 'naruto is like darth vader fanfiction', their journey of self - discovery could be seen as similar. Naruto has to constantly figure out his place in the ninja world and how to control his power. Darth Vader is on a journey of self - discovery too, as he grapples with his identity as Anakin Skywalker and his role as Darth Vader. They also have a sense of isolation in some ways. Naruto often feels alone in his struggles, and Darth Vader is isolated in his dark armor, cut off from his former self and many human connections.
One interesting plot twist could be that Darth Vader is actually related to one of the Avengers in some way. Maybe there's a long - lost family connection that changes the whole dynamic of the fight. Another could be that the power source of the Infinity Stones somehow combines with the Force, creating a new and unexpected power that either Darth Vader or an Avenger has to control. It could also be a plot twist where the Avengers think they've defeated Vader, but he actually uses a Sith technique to possess one of them and turn the tables.
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.