6. Jack Harkness and The Immortal One have a LOT in common
Handsome, charming, charismatic, immortal and, er, not opposed to a spot of sweet, sweet loving: we could be describing either Buffy’s Immortal or Doctor Who’s Jack. Who’s to say that they aren’t…. dun dun dun… THE SAME BEING?
We all know there’s a large chunk of time when Jack’s been unaccounted for; he did say he loved travelling through Italy in his rogue Time Agent days. And it just so happens Italy is one of The Immortal’s favourite haunts too.
Someone’s even written a full fanfic about The Immortal/Jack.
7. The Master gives both Buffy and The Doctor a fair bit of bother
Ok, so one’s a vampire and the other’s a Gallifreyan Time Lord, but there’s a fan explanation for that.
What if Roger Delgado’s Master found himself trapped on earth, was bitten by a vampire and then regenerated into the bloodsucking fiend who gives Buffy so much trouble?
And just like John Simm’s Master, Buffy’s Master is resurrected (off screen in the comics) by a group called the Seed of Wonder. He ends up being killed by a higher being, though.
Who knows what those Gallifreyan Time Lords can do when they get together to take down one of their own…