10 Classic Doctor Who Enemies Who Need To Return

Out of all of the enemies the Doctor has faced, few have been quite so celestial as the Black Guardian. Both he and his benevolent counterpart - the White Guardian - were introduced in the 16th season's Key to Time arc. Here, they were introduced as personifications of cosmic concepts, with the White representing order and the Black representing chaos.

During his first meeting with the White Guardian, the Fourth Doctor was tasked with finding the six pieces of the Key to Time, before the Black Guardian could. Naturally the Doctor and his new companion, Romana, were successful and the Black Guardian was defeated. He'd return a few years later though, for a trilogy of stories during the show's 20th season. Here, he manipulated Vislor Turlough, an exiled alien living on Earth, into becoming the Fifth Doctor's companion so that he could kill him. Once again though, the Guardian was defeated and Turlough chose to stand by the Doctor's side.

It's interesting to note that the Black Guardian's two stints on the show were both in rare moments of long-form story arcs spread across multiple stories - something which was uncommon for classic Who. It's clear then that the respective creative teams saw the character's potential as a large-scale threat. This demonstrates that he'd fit in perfectly with the modern era, perhaps in a heavily serialised Flux-style story. Especially since it would be nice to know just how the Guardians of Time were affected by that little old Time War.