10 Best Buffy The Vampire Slayer Villains

Watching loveable, innocent Willow turn evil in season six was seriously hard to watch, but boy was it entertaining. With her magic addiction growing out of control throughout the majority of the season, culminating in her being left by girlfriend Tara, getting clean and getting back with Tara, everything comes crashing down when Warren kills the love of her life in cold blood.

Unable to bring her beloved back, Willow embraces the dark arts in order to kill Warren, Andrew and Jonathan. Her rage and power cause her to be become a completely different character - Dark Willow, intent on killing those who ruined her life and, eventually, sure that destroying the world is the only way to set things right.

Thanks to her immeasurable power, she is able to overpower Buffy, Anya and Giles (who comes equipped with his own magical knowledge) and lets her rage overcome her when she kills Warren and attempts to kill her own friends. Eventually stopped from continuing on her deadly path by Xander, Dark Willow was one of the show's most personal and heartbreaking villains - and one of the most powerful beings in the entire franchise.