After being stranded in Pete's World in Doomsday, Rose travels the world for Torchwood. It's in Africa that she runs into Xander Harris.

After the destruction of his home and the death of Anya, Xander travels Africa in search of Slayers. It's there that he meets Rose Tyler.

Rose makes news among the locals for her violent tendencies toward nasty entities that she believes to be malevolent aliens. Xander must investigate the claims about the white woman killing the demons that fill the stretches between villages.

I'd prefer Rose not actually be a Slayer, but that's up...

When the monks decided to send the Key to a Champion, they shopped around a bit. Sure, there was the Slayer, but the world was simply full of Champions, heroes and Hellblazer types.

There was also Duncan MacLeod, the Immortal who had defeated Ahriman. If he could take down an evil older than word, surely he could protect the Key.

Thus, they sent the girl to him in the most heart-wrenching form: as the daughter he had adopted with his dead love, Tessa.

Must:
Tessa must be dead and have died at the approximate time she did in canon (October '93). For pathos' sake, ...

When nuns start to go missing, leaving behind little more than blood splatter and bone chips, the Watcher's Council takes notice. Enter Faith, who has taken on a new role since the destruction of Sunnydale; namely, as an undercover operative to assess and solve supernatural mysteries.

Chuck Bartowski - the Intersect - is confused when he flashes on a nun and learns about demons and magic, seeing the truth about 2003's Sunnydale Disaster, learning about cells of terrorists around the world composed entirely of young women and teenaged girls of every race, religion and nationality.
...

This is a crossover with fashion dolls media - Barbie, Bratz, MyScene, et cetera - where the dolls are characters.

One of the Scoobies goes to university and is assigned campus housing with a group of fashion dolls. I'd prefer Dawn, but anyone is fine. How does s/he deal with Cloe and Jade's superficiality, Barbie's overacheiving, or Hudson's soccer and River's rocking out? And is Barbie majoring premed, prelaw, early childhood education, astrophysics, culinary arts and journalism?

Oh, and if you go with Barbie, a sub-plot where either:
-we find out that Krissie isn't rea...

How it hasn't happened yet, I'm unaware. Buffy the Vampire Slayer/Jennifer's Body crossover. There are spoilers for the end of the film in this challenge.

Post-Season Seven of BtVS (AU is fine, too, as long as there's a Watcher-type council which the Scoobies are a part of, and there are many Slayers). Post-Film for Jennifer's Body (including possible end shift).

While the Scoobies/New Watchers wouldn't normally investigate a place with such an obvious name as "Devil's Kettle" (Hello, Sunnydale!), mystical energy emanating from the town causes some alarm. Especially when if b...