Whistler is an enigmatic demon who appears in Season Two, and is played by Max Perlich. He first appears in a flashback in the episode "Becoming, Part One" in which he approaches a dirty and destitute Angel on the streets of New York City. He describes his duty as maintaining the balance between good and evil, and claims that Angel is destined to be a force of good. He then takes Angel across the country to Los Angeles where he points out the young Slayer Buffy Summers as she is called to her destiny, and later at her home, where she is clearly distraught over her Slayer duties and hearing a massive argument between her parents. Seeing her allows Angel to decide to turn his life around, and to help Buffy in her duty as the Slayer. Whistler does not interfere again until he learns that Angel, now without a soul, plans to awaken the demon Acathla. He confronts Buffy and tells her that Angel was never supposed to lose his soul. In fact, it had been his destiny to stop Acathla, not bring him forth. He informs Buffy that she will have to kill Angel to stop Acathla if he is awakened, which ultimately comes to fruition. Whistler was originally supposed to appear in "Angel" as Angel's guide and link to the Powers That Be, but was replaced by the character Allen Francis Doyle.