I haven’t successfully figured out what Vader’s feelings toward Palpatine would be in the timetraveling vaderwan au. Palpatine never overtly moved against Vader, asked for his help and ‘gave ‘help’‘ in return. Sure, he lied and was a sith lord, and asked Anakin to do horrible things that went against Anakin’s nature
but post “you TRICKED me” hurt feelings, IDK how he’d feel??? like??? would he still try to talk to and reason with Palpatine?? Obi-Wan and the Order have asked Anakin to do a lot of things he didn’t like??????? some of which resulted in his mother being tortured to death, so??????????
i mean, he’s successfully talked Knight!Obi around to his side of things again. I feel like at this point, Vader would also be interested in trying to talk Palpatine around to his way of thinking. “Look. The Jedi aren’t that bad, we can still save them! Change their ways!!”
(meanwhile this timeline’s palpatine is just “who the fuck are you - better hurry up and bullshit my way through this so I can figure out how to use it to my advantage”)