Doctor Who: 10 Worst NuWho Villains

It's one thing for a villain to be bad, but it's another thing for them to swoop in at the last minute and completely ruin an otherwise solid story.

That's the crime that Series 7 villain the Shakri is guilty of, with the character turning up out of the blue at the end of The Power Of Three, doing basically nothing, and then vanishing almost as quickly as he appeared.

Before this point, the episode had built up a fun and intriguing mystery about billions and billions of small black cubes that appeared across the Earth overnight, each of them packing their own unique behaviour - one cube might play music, another might fire a laser, another might subscribe to WhoCulture, and so on.

But when the Shakri turns up and starts explaining the purpose of these cubes in a boring and monotone voice, all this intrigue and mystery evaporates in an instant.

The cubes' purpose isn't even interesting (they're a weapon to kill humanity, yawn), and neither is the Shakri's motivation, which is "humanity is a plague that must be stopped". Why are we a plague? Why must we be stopped? Well, that's never really delved into. Great.

To put all of this another way, the Shakri never needed to be here and the cubes should have gone unexplained (thus sparking fan discussions and theories about their origins). The episode would've been a hell of a lot better in that scenario.