What do you think "seduce" means, exactly?
To lead astray, to persuade, to win over, attract, entice.
In ESB, Vader was toying with Luke. Vader was basically fighting with one hand tied behind his back, until he finally put an end to the one-sided fight by chopping Luke's hand off. Vader (looking to turn Luke, not kill him) reveals to Luke that he's Anakin Skywalker, and that he turned to the Dark Side, and Luke can do it too. "If only you understood the
power of the Dark Side."
By RotJ, Luke has improved his lightsaber skills, so now he's holding even with Vader, but it's not enough, and Luke seems resigned to the fact that he might die. But Vader threatens that Leia is next. If Luke doesn't stop Vader, Leia will be the one getting tortured and killed, assuming she doesn't turn to evil. Luke gets mad and starts delivering an angry beatdown, while the Emperor looks on in triumph, because anger is a path to the Dark Side, and this angry beatdown is the tantalizing "power" that Vader said Luke needed to understand. Luke chops Vader's hand and realizes the parallels between himself and Vader, realizes that he's becoming Vader, so he stops and rejects the Dark Side, to his mortal peril, until it turns out that Luke was right, and Vader didn't have it in him to let the Emperor murder his own recently-reunited son right in front of him.
In RotS, Anakin loves Padme so much that he monologues about how he can't think straight anymore (a convenient solution to logical character development). He learns that Padme is going to die, and Palpatine says that the Dark Side can cure her, if only Anakin kills Mace Windu and swears his loyalty to the Dark Side. Anakin does it. Palpatine: "Good Anakin, now we can begin our research on how to save Padme, which is something I currently don't know how to do." That's not seduction, that's a trick.
Then Anakin kills children, force-chokes Padme (because he's twisted beyond all reason, working against even the entirety of his thin character), potentially causing her childbirth-death (except for the movie stating that she died of loneliness and broken heart while holding her own newborn children), and then he gets his legs chopped off and burned to near death by Obi Wan. And with Padme dead at Anakin's hands (directly blamed on Dark Side anger by the Emperor), the "cure Padme" issue never comes up again, and Darth Vader remains loyal to Palpatine (in the Dark Side way) for the next 20 years or so. "If only you understood the
power of the Dark Side, you could totally score a major kill count against helpless children. If only you understood anger, you'd have the power to kill that bitch Padme."
Also, the prequels pretty much took away Darth Vader (as a betrayer and Jedi turncoat) "helping the Empire hunt down and destroy the Jedi knights."