There is no shortage of great villains when it comes to Star Trek. Khan Noonien Singh is prominent and has forever left his mark on pop culture. The Borg Queen came along and left her mark many years later. That whale probe from Star Trek IV: The Voyage Home came from... where exactly? Could it come back? What other extinct creatures might it want to talk to? Look out.
Still, for true villainy in Trek, no one can touch the resident antagonist of Star Trek: Deep Space Nine.
He was there in the beginning, and he's there in the end. Sometimes our crew had to help him, save him, argue with him, etc... but once Cardassia joined the Dominion (in a deal struck by him), the battle lines were drawn. We're of course referring to Gul Dukat, played to perfection by Marc Alaimo.
Dukat became really popular with fans, to the point where his horrific, fascist, and cruel actions during the occupation of Bajor began to be defended by fans online. This would not do. The decks needed to be cleared in Season 6, especially after Dukat lost his daughter at the same time he lost Deep Space Nine for a second time.
That is partially how we ended up with "Waltz." It's (mostly) a two-hander that features Dukat and Sisko (Avery Brooks, matching Alaimo line for line) in a cave, and these two have stopped being polite and are getting real. Dukat is going insane, he cannot shut up, and Sisko has to try and deal with it. The real truth of Dukat is finally spelled out as clear as can be: he hates the Bajorrans, he always has, and he wishes that he'd killed every single one of them. He ends the episode promising that Bajor is dead.
If fans didn't get that Gul Dukat was a VILLAIN before, then this episode clears that up nicely. Captain Sisko gets it for sure — at the end, he now realizes that it's gonna come down to the two of them. The Emissary is correct, because that is exactly how things end up a season and a half later.
Welcome back to Warp Factor where we are putting Gul Dukat on trial, and exploring "Waltz" to get all of the necessary EVIDENCE. He is the worst, and we have the receipts. Watch below.