The Master is a fictional character on the action-horror / fantasy television series Buffy the Vampire Slayer (1997 -- 2003). He is a centuries-old vampire portrayed by Mark Metcalf, determined to open the portal to hell below Sunnydale High School in the fictional town of Sunnydale where the main character Buffy Summers lives. The premise of the series is that Buffy (Sarah Michelle Gellar) is a Slayer, a teenage girl endowed with superhuman strength and other powers which she uses to kill vampires and other evil beings. Each season of the series Buffy and the small group of family and friends who work with her, nicknamed the Scooby Gang, must defeat an evil force referred to as the Big Bad; the villain is usually trying to bring on an apocalypse. The Master is the first season's Big Bad.

Who plays the master in buffy season 1? Let's have some stream of consciousness first.
The relevant information to answer the above question is: He is a centuries-old vampire portrayed by Mark Metcalf, determined to open the portal to hell below Sunnydale High School in the fictional town of Sunnydale where the main character Buffy Summers lives. So, the answer is Mark Metcalf.