7 pieces of evidence that suggest Doctor Who and Buffy The Vampire Slayer are set in the same universe

The Time Lord theories don't stop there, though: some would have you believe that Buffy is a Time Lord, and that the whole Slayer line is one continuously regenerating Time Lord… though that one doesn't exactly stand up. Faith is hardly a regeneration of Buffy, is she?

There's also an argument that Rose could be a Slayer who never got the call, and that's why she was able to take on all that energy from the Time Vortex. And it could explain why she and the Tenth Doctor appeared to pop up in a Buffy series 8 comic...

4. Both Buffy and the Doctor have dealings with a teenage girl who's actually a mystical Key in human form

We known Buffy character Dawn Summers was a mystical power of living energy, known as The Key, before a ritual transformed her into an ordinary teenage human girl. This clearly means she's yet another incarnation of Doctor Who's The Key to Time, part of which turned out to have been transformed into a teenage girl called Princess Astra of Atrios.

Just like Dawn and Buffy antagonist Glory, Astra had a God-like figure called The Black Guardian chasing after her. Imagine the showdown between those two? It'd take both Buffy and the Doctor to restore order.

5. Both Angel and the Doctor have to deal with demons who possess their pals

Remember that time Angel's Fred was possessed by Illyria, an ancient demon whose people turned on her, destroyed her and left her body to rot beneath the earth while her mind lived on? Well, it sure does sound similar to Classic Who story arc The Hand of Fear.

Sarah Jane Smith had her mind taken over by Eldrad, an ancient and powerful alien whose people turned on him and killed him. He too was buried beneath the earth, but his hand made its way into the future, where Sarah Jane came into contact with it and found herself under his control.

And when both beings returned to their homelands, they discovered that millions of years had passed and they were all alone.