I think Darth Vader should yell "Nooooooooooooooooo" a lot in the OT.

The Death Star blows up. Vader in his spiraling fighter: "NOoooooooooooo!"

Millennium Falcon jumps to warp, just escaping the Empire's grasp off Bespin: "Nooooooooooo!"

Vader can't find Obiwan's body after the killing blow. "Noooooooooooooo!"

Luke lets go and falls down the chute at Cloud City, foiling Vader's plan to convert him to evil. "Nooooooooooooo!"

Tarkin orders Vader to stop choking Ozzel. Would our antihero really say "As you wish"? On the contrary: "Nooooooooooooooooooooo!"