Angel (season 1)
At the end of the third season of "Buffy", the 242-year-old, re-ensouled vampire Angel left Sunnydale to give teenage Slayer Buffy Summers the chance to live a normal life. Angel is now living in the big city of Los Angeles. With Buffy gone Angel is now completely cut off from society, every day getting closer and closer to giving in to his vampiric hunger. It's not until he befriends the half demon and fellow Irishman Doyle, who is sent visions of people in trouble by The Powers That Be, and fellow Sunnydale resident Cordelia Chase, who grounds Angel's life in the humanity around him, that he truly begins to take charge of his life and seek atonement for his past sins. He sets up his own detective agency, Angel Investigations and begins to "help the helpless".
Darla (Buffy the Vampire Slayer)
Darla's role in the franchise increased dramatically after her resurrection by the law firm Wolfram & Hart in the final episode of "Angel"'s first season, titled "To Shanshu in L.A." In the second season opener, "Judgement", Wolfram & Hart lawyers Lindsey McDonald and Lilah Morgan question Darla about her past. She talks of how she can feel Angel, and slowly her memory begins to return. In the episode "First Impressions", Angel begins having romantic dreams about his maker. The dreams sap his strength. In "Dear Boy", Angel is shocked to see Darla walking the streets. When he tells his partners, Wesley Wyndam-Pryce and Cordelia Chase, they think he is starting to lose his sanity. During the course of a stakeout by Angel Investigations of a woman suspected of having an affair, Angel confronts the woman, who looks exactly like Darla. She claims she is DeEtta Kramer. When she runs away from him, she walks outside into the sunlight, meaning Darla has not only been resurrected, but is now human. However, Darla and Lindsey's plan to convert Angel back to evil fails. In the end, Wolfram & Hart bring in Drusilla to make Darla a vampire again after her syphilis returns and she starts to die. Ironically, she is turned back into a vampire as she accepts her fate after a failed attempt by Angel to save her. Drusilla and Darla unsuccessfully attack Angel and leave Los Angeles.