Barney (Buffyverse)

''"Okay, sure, I'm a demon, I'm evil - but I not evil evil.." ''~ Barney (trying to gain Angel's trust)

Barney was the true antagonist of the Angel episode "Parting Gifts" but didn't reveal himself as such until midway through - he was an empathic demon and serial-killer as well as an auctioneer in the black market: it is also almost certain Barney was a sadist as he would of been able to feel his victims' fear and pain yet took delight rather than remorse out of the misery he inflicted.

History
Despite his unthreatening appearance, Barney was a sadistic murderer and an auctioneer of body parts of demons and other empowered beings. Barney sought the help of Angel Investigations when he was being tracked down by a demon hunter, who turned out to be Wesley Wyndam-Pryce, who was actually tracking a Kungai demon, who Wesley believed was responsible for a number of deaths that had actually been caused by Barney himself: in reality the Kungai was merely tracking Barney in order to exact revenge for the removal of his Tak horn (which resigned the demon to a slow and painful death).

Barney played the part of a nice guy while being left alone with Cordelia as Angel sought out clues (Wesley tagging along despite Angel's reluctance to have a partner following the death of Doyle). However when Cordellia explained to Barney that she had recieved Doyle's gift of prophecy the demon dropped his guise and attacked her emotionally, preying on her guilt over Doyle's death and despite being reluctant to knock her out as "bruises lower the price" he decided to do so anyway when she tried to run away.

Barney took Cordelia to the Los Angeles Ramsay Hotel, where he held his auctions alongside his partner Hank (who appeared to be human but was never truly fleshed out - though he was pretty sadistic as well, thus he could of been a demon of some sorts or merely a disturbed human). Barney sold the Tak horn for 20,000 U.S. dollars and then proceeded to auction Cordelia's eyes, which were purchased by Mac, a Wolfram & Hart lawyer and regular bidder, for 30,000 U.S. dollars.

After the auction Mac said that she would not be needing Cordelia's body and got into a brief argument with Barney over his insistance she would have to pay an extra thousand dollars for the "eye removal" services - eventually she agrees and Hank is delighted only to get into a rather morbid (but twistedly amusing) argument with Barney when Barney insists on doing the eye removal himself - Hank seems devastated he isn't getting to do the task and Barney simply notes that Hank is embarassing himself. In part due to this Angel and Wesley have enough time to enter the building and storm backstage, as Barney's men attack Angel he gets into a brawl with Wesley but is more than a match for Wesley - until Cordelia grabs the Tak horn and stabs Barney in the back with it, causing Barney to dry out and disintegrate, killing him instantly (as a Tak horn has the power to drain life-force out of whatever it touches).