Supernatural: Every Major Villain Ranked Worst To Best
2. Azazel
The Big Bad that started it all, Azazel (or simply Yellow Eyes) kicked off the entire series we now know and love.
Azazel was tasked with finding a worthy vessel for Lucifer's eventual return, which eventually would lead him to the Winchester/Campbell family.
Old Yellow Eyes previously made a deal with Mary to save John, Sam and Dean's father. But when it came time to collect and begin the process of turning Sam, Mary tried to stop him, resulting in her death and kickstarting the decades-long vendetta between Azazel and the Winchesters.
Originally thought to be the overarching villain, the long-awaited victory against Azazel is short-lived and only the beginning of Sam and Dean's problems.
Without Azazel, there would be no Supernatural, and the boys would never have become the badass demonslayers they are today.