Warning: SPOILERS ahead for Legends of Tomorrow season 5, episode 7, "Mr. Parker's Cul-De-Sac."
The latest episode of Legends of Tomorrow ended with the death of a major Arrowverse villain: Damien Darhk. In a surprise turn, Darhk committed suicide after finding a way to redeem himself in the eyes of his daughter and trying to ensure that she'd be happy and provided for once he was gone.
Played by Neal McDonough, Damien Darhk was perhaps the most persistent villain to plague the Arrowverse. A master of the dark arts and collector of evil artifacts, he first appeared as the chief villain of Arrow season 4. An earlier version of Damien Darhk became part of the Reverse Flash's time-traveling Legion of Doom during the second season of Legends of Tomorrow, and a resurrected Damien Darhk led the efforts to free the time demon Mallus during Legends of Tomorrow season 3. The warlock did find some measure of redemption in death, however, sacrificing himself to save his daughter, Nora, from becoming Mallus' host. Since that time, Nora gave up dark magic for the life of a fairy godmother and began dating The Atom.
His selfless death was not enough to save him from Hell, but "Mr. Parker's Cul-De-Sac" found Damien Darhk returning to Earth as an Encore. However, before he got down to the serious business of spreading misery and dooming other souls to the same dark fate as himself, Darhk couldn't help but check up on his daughter and see what she'd been doing over the past two years. Unfortunately, Damien came to call on the night that Ray Palmer (whom Damien had never liked) was planning to propose to Nora after arranging a romantic dinner at the home of their fellow Legend, John Constantine.
What followed was an epic farce, as Nora pretended to be dating John Constantine, who was the sort of scoundrel her infamous father would approve of. She also pretended to be an evil witch who had Sara Lance and Ava Sharpe as thralls rather than friends. In the end, the truth came out, and Damien eventually accepted Nora for who she truly was and that, for better or worse, Ray did make her happy. Granted, it did take one murderous rampage and a bit of fairy godmother magic to make it happen, but Damien ultimately admitted that he had ruined Nora's life by trying to make her decisions for her and apologized for it.
The episode ended with an impromptu wedding, which all the Legends attended. Damien gave the bride away and made peace with Ray Palmer, though he did promise to come back and kill Ray if he failed to take care of his "Nora doll." Darhk even tried to make peace with Sara Lance, but she was less than receptive given that Darkh had murdered her sister, Laurel. Darhk accepted her refusal to shake his hand as he left the reception party, smiling sadly as he said "I know you'll never forgive me. To tell you the truth, I won't either."
Sara didn't realize until a moment too late that Darhk had taken her Hell-forged sword; the only weapon capable of killing an Encore by permanently destroying their soul. Sara found her archenemy outside of Constantine's house, just as he had impaled himself with the sword and his body crumbled to ash in a burst of green fire. Thus perished one of the greatest villains the Legends of Tomorrow ever faced, apparently preferring oblivion to an eternity in Hell.