I can’t imagine Vader saying “Liar!! You’re with him! You brought him here to kill me!”
No, he just said: “You are part of the Rebel Alliance and a traitor! Take her away!”
Prequel Anakin would have said something like “Traitor!! You’re with the Rebels! You’ve turned against us!! I will not let you get away with this!” or whatever.
Someone should do a fanedit of the OT with Vaders dialogue rewritten in a Prequel Anakin-esque fashion with James Earl Jones voice recreated by AI. Here are some suggestions:
When Vader interrogates Captain Antilles he could say:
“I’m haunted by the plans that you are hiding from me.” […] “Where are they? Tell us. TELL US NOW!”
The “Bring-my-shuttle” scene in Empire:
“This is outrageous! How can he lose a hand and not join me!? It’s unfair!”