10 Times TV Heroes Became The Bad Guy In Their Own Show
3. John Mitchell - Being Human (UK Series)
From the very first episode we knew vampire heartthrob John Mitchell wasn't always a good guy, but in the present tense of the show he seemed to be trying to turn over a new leaf.
As the tormented blood-thirsty piece of the original trio, it made sense that on occasion he would come close to showing off his fangs and sinking his teeth into a baddie or two.
It was a huge development for the character, when close to the end of the second series an enraged Mitchell and another vampire massacre over twenty people on a train. It's one of the only times we saw a truly villainous Mitchell, and it might be his most iconic. While Mitchell had killed scores of people before, to know he was killing out of anger rather than his uncontrollable urges made us like him a heck of a lot less.
The massacre becomes an integral part of the plot carried into the third series, and is ultimately the guilty reason for Mitchell's death. As George tearfully plunges a stake through his chest, we're left knowing that Mitchell didn't die a hero, but simply a mass murderer who will now get away for his crimes.