Evil characters do evil things, of course. Otherwise they wouldn’t be evil. But sometimes it’s evil for a broader purpose (e.g., “You have violated our sovereign territory, Jack Bauer, so we are going to kidnap and torture you to discourage any other do-gooders from following suite”) and sometimes it’s evil for a the sake of being evil.
Want an example of the latter category? Try the Buffy the Vampire Slayer episode “Selfless,” in which
the episode’s villain of the week, a demon lord named D’Hoffryn, is vexed because one of his minions–series regular Anya–wants to tread the straight and narrow path and undo a murderous action she committed earlier in the episode. He expresses his vexation by murdering another of his minions–Anya’s only friend–in front of Anya.
But that’s just off the top of my head. I’m sure my fellow Dopers can come up with better ones.
I think that may have served a larger strategic purpose, though; Alderaan was a major supporter of the Rebel Alliance, and blowing it up was intended to terrorize the rest of the Empire into submission.
Wouldn’t Iago in Othello be pretty much the classic example of pure, spiteful evil?
Buffy gives us plenty of evil for the sake of being a dick examples.
Spike. He’s just a dick for most of the series. He kills slayers for the sport of it.
Drucilla. Chick is just nuts. She loves inflicting pain for the sheer joy of it.
The scene in Kings Row from which Ronald Reagan gets the title of his autobiography Where’s the Rest of Me?
The Doctor (Claude Rains) never approved of (Reagan’s) romance with his daughter and was even more upset when (Reagan) decided to break up with her (for Ann Sheridan which is kinda understandable) – so in retaliation the non-invisible Doctor amputates Reagan’s legs, even though it was totally not necessary his condition in no way justified it.
That stayed with me a long time. It was major-league ugly & everyone’s performance was worthy of the pics 3 Oscar nominations.