“I am altering the deal. Pray, I don’t alter it any further.”

In Star Wars Episode V: The Empire Strikes Back, makes an affect Lando Calrissian. Lando gets to deliver Han Solo to Jabba the Hutt, and Vader gets… Well, Vader gets whatever he wants. Yes, he says that he only wants Luke, but when that doesn’t compute, Vader changes his mind and needs to require Leia and Chewbacca also. sort of a true villain, Darth Vader will do anything it takes to succeed in his goals.

In this quote, Vader is threatening Lando, all the while maintaining civility. He makes himself bent to be a benevolent ruler, who is showing kindness to at least one of his undeserving subjects. Vader knows that he’s a force to be reckoned with, and emphasizes to Lando that only straightness and compliance can keep his inner rage bay.