where did buffy's sister come from in season 5
Dawn Summers Dawn is first introduced as Buffy's (Sarah Michelle Gellar) younger sister at the end of Buffy season five premiere "Buffy vs. Dracula", though Buffy had been previously established as an only child. Initially, the mystery of Dawn's sudden existence is not acknowledged in the series, with the other characters accepting her as a part of the status quo. Four episodes later Buffy discovers Dawn is in fact a mystical object known as The Key; a group of monks transformed The Key into human form and sent it to the Slayer for protection from the villainous Glory (Clare Kramer). The memories of Buffy and her associates were altered, along with relevant records, so that they believed her to have always existed as Buffy's sister. She is shown to look up greatly to Willow and Tara and has a crush on Xander. She also is friendly with Spike, who is as protective of her as Buffy herself. When Dawn learns of her origin, she resorts to self-harm and runs away from home, until Buffy assures her they are real sisters no matter what, securing it with a blood oath. Her relationship with Buffy, having been portrayed with a typical sister dynamic in the first half of the season, changes when she discovers what she is. The two become closer as Dawn becomes Buffy's sole focus once she drops out from college to protect her, going as far as to warn her friends she is prepared to kill anyone who attempts to go near Dawn in the finale. Dawn suffers more pain when her mother (Kristine Sutherland) dies unexpectedly from a brain aneurysm, which leads to Dawn resorting to black magic to try to bring her back from the grave, an action she immediately reverses upon realizing the consequences of her actions. It is eventually revealed that Dawn's purpose as The Key is to open portals to alternate dimensions, a power the hell-god Glory wishes to exploit to return home. When Glory successfully uses Dawn's blood to break down the dimensional barriers, Buffy sacrifices her own life, realizing that their blood is now the same, to end the apocalypse and save Dawn. Buffy's sacrifice also neutralizes the power of The Key, giving Dawn the opportunity of a normal life.
Angel (Buffy the Vampire Slayer) After his departure from Buffy, Angel appeared in his own spin-off series, titled Angel. Moving to Los Angeles, he starts a supernatural detective agency called Angel Investigations. He dedicates himself to "helping the helpless," and becomes a Champion of The Powers That Be, who send him psychic visions through his employees Doyle (Glenn Quinn), and later Cordelia (Charisma Carpenter). In doing so, he frequently clashes with the powerful law firm Wolfram & Hart, who represent the evil of the world. During this season (1999â€“2000), Buffy and Angel appear in each other's shows (the Buffy episode "Pangs" and the Angel episode "I Will Remember You"), but are forced to accept that nothing has changed and they still can't or shouldn't be together. Later in the television season, Buffy crosses over into the episode "Sanctuary" where she attempts to kill rogue Slayer Faith (Eliza Dushku) to whom Angel shows compassion, and Angel appears in Buffy's "The Yoko Factor" where he squares off with Buffy's new boyfriend Riley (Marc Blucas). They finally decide to stay away from each other's business and stick to phone calls at this point. In the season one finale, Angel is given some hope at redemption when the Shanshu prophecy reveals that a vampire with a soul may eventually become human after fulfilling his role in the upcoming apocalypse.