Harmony Kendall (born presumably in 1981 in Sunnydale, California) is a fictional character created by Joss Whedon for the cult television series Buffy the Vampire Slayer and its spin-off Angel. The character is portrayed by Mercedes McNab. Originally cast as a minor character, Mercedes McNab's credited status elevated to guest star, "special guest star" and ultimately series cast over the course of her tenure in Buffy and Angel. Harmony holds the distinction of being the only character to appear in both the Buffy unaired pilot and the Angel series finale.
Harmony appeared in the unaired pilot as a member of Cordelia Chase's clique, the "Cordettes." She subsequently appears in the second episode of Season One, "The Harvest," and makes minor appearances throughout the first three seasons, and then a slightly larger role in another two. When Cordelia begins dating Xander Harris, Harmony shuns her from their clique and usurps her position as leader of the group. After Cordelia and Xander's breakup, Harmony cruelly tricks Cordelia into thinking that she has been re-admitted into the clique, only to humiliate and reject her. After a vengeance demon grants Cordelia's wish that Buffy had never arrived in Sunnydale in the episode "The Wish," Harmony appears in the alternate, hellish reality as a more subdued version of herself, again a follower of Cordelia's "Cordettes."
In the final showdown with Mayor Wilkins during his Ascension in the episode "Graduation Day," Harmony is killed/sired by a vampire. She reappears in the episode "The Harsh Light of Day" as a vampire, having retained her characteristic pettiness, susceptibility to stronger-willed people, and an affection for unicorn figurines (which, in Angel's fifth season, is undiminished). Harmony begins a sexual relationship with Spike, her "blondie bear." Neither Spike nor Harmony are satisfied with their relationship; Spike is frustrated by Harmony's ignorance and clinginess while she is exasperated with his endless broken promises and repeated attempts to kill Buffy. They separate, although she agrees to rekindle their relationship after Spike escapes from the Initiative. Harmony quickly regrets this decision after recognizing Spike's renewed campaign against the Slayer, and even chases him out of her lair with a stake when he desperately seeks her help in the episode "Pangs."
Spike's ambition to kill the Slayer apparently rubs off. After separating from Spike, Harmony wants to be an independent, strong vampire who can get by on her own; accordingly, in the episode "Real Me," she gathers her own gang and makes her own attempt to kill Buffy, which ends in disaster. Her minions destroyed, Harmony returns to Spike for protection until it becomes clear that Spike's infatuation with Buffy has become an obsession (cf. "Crush").
Several years later, Harmony tries to make a life for herself in L.A. She gains employment at the L.A. branch of Wolfram & Hart, as a member of the secretarial pool. Harmony is attracted by the building's necro-tempered glass windows (designed to protect vampires from sunlight which would otherwise cause them to burst into flames), as well as the firm's non-judgmental workplace culture and dental plan. A few weeks into her employment with the firm, Wesley Wyndam-Pryce hires her out of the blue to be Angel's new personal secretary, after Angel and his staff are given control of that branch of Wolfram & Hart; Wesley apparently thought that a familiar face would be good for Angel. Angel reluctantly agrees, on the strict condition that Harmony refrains from drinking human blood (she notes at that time that she has already been off human blood for several months).
Harmony is reunited with Spike when he returns, first as a ghost and then in corporeal form. She tries to connect with him, and initially hopes to renew their relationship now that he has a soul. Spike shows no interest for Harmony until he regains his corporeal form and proceeds to seduce her into a brief, disastrous fling, after which neither of them puts any effort into rekindling their tumultuous relationship.
At this point in her un-life, Harmony feels isolated and alone. She knows that she is incompetent as an evil vampire, but her struggle to lead a more normal life is hindered because she lacks a soul. Angel often treats her with distrust and barely-masked hostility, and her input, ideas, and presence are generally ignored by his team. Harmony also experiences an inability to connect with her co-workers, who resent her quick rise to the position of the CEO's secretary. In the episode "Harm's Way," she is framed for murder by Tamika, another vampire secretary who wants her job; Tamika also substitutes human blood for her supply of otter blood, to make it appear as though Harmony drank from the victim. She clears her name and ironically saves a demon summit by staking her scheming rival on a conference table with a pair of chopsticks. Despite her incompetence, Harmony manages to prove a 'sort of' asset to the team, 'torturing' Eve (i.e. hitting Eve in the face a few times) to get information, helping Wesley search for information about Knox's plans, and aiding Lorne in protecting Eve from her replacement as their liaison to the Senior Partners. She strikes up a brief friendship with Fred Burkle, though her relationship with Illyria, the demon who later inhabits Fred's body, is quite frosty.
Harmony becomes a member of the regular cast starting with the episode "Underneath". In the series finale, "Not Fade Away," she betrays Angel, revealing his plans to go after Archduke Sebassis to Marcus Hamilton, the Senior Partners' new liaison, with whom she has a sexual relationship. Angel, however, always expected her to betray him at some point, so he had only confided information that he wanted her to reveal. After her betrayal (which Angel blames on her lack of a soul, and she blames on his lack of confidence in her), he fires her, but not before providing her with a letter of recommendation (which he had already written and signed, in anticipation of her disloyalty). As Angel and Hamilton prepare to fight each other, she runs off, wishing them both luck: "May the best man win!" Her current whereabouts are unknown, but it is clear that somehow before the final battle Harmony managed to escape Los Angeles, as she manages to make an appearance in Buffy the Vampire Slayer season eight.