Ok this is a baby bunnie and not a full blown bunnie

Time adjustments are required.

The Scoobies on their way toward Cleveland after the fall of Sunnydale pass through Peoria, IL where they meet a young policeman by the name of Tony DiNozzo and a friendship is made.

Over the years they have maintained their long distance friendship.

Now depending on how you want to play this you could have a director find out about Tony's friendship with the Council and try to use it for political gain or view Tony as being friends with terrorist. You could also have Council come to visit NCIS and the director making a big thing about it only to have them snub him/her.

One night Xander Harris dress up for Halloween in some old fatigues that had previously been owned by one John Eric Winchester. That night when Ethan Rayne called upon Janus to power the spell that he has cast on the costume; John's soul and sub-conscious were sucked into Xander's body.

Many years have past since that night and John forgot all about it, chalking it up to a head injury he received while fighting some evil creature. So when John called up Y.E.D. to save Dean's life in exchange for his own life, soul, and the Colt he never thought that someone else had prior claim on his souls.

To put it simply John was a little pissed off when he woke up after his death to find himself in he body of a younger man with one eye, surrounded by a bunch of teenage girls with a voice in the back on his head cursing in a number of different languages.

After reading Keira Marcos excellent story Tangled Destines, this popped up

What if Xander had the combined powers of Telepathy & Empathy from the onset of puberty due to either being psionic, part alien, natural born witch, mutant or power transfer? He would be able to fully see into the mind & heart of everyone around him honestly without any form of willful or unwillful deception. And if he has something similar to a Psionic Legacy as in Tangled Destines from a loved one, or multiple loved ones, he would be much more secure, self aware & independent psychologically, as he would know their unconditional love, affection, honesty, respect, comfort and acceptance as well as possibly gain the full knowledge of how to use the full breath of his abilities effectively, efficently and ethically whilst still fully protecting himself. Would lead to much distrust regarding Willow and later the scooby gang.

Possible Psionic Legacies could come from a deceased parent, uncle, grandparent, godparent or his best friend/possible lover Jesse 

To be possibly crossed with Supernatural, Charmed, Star Trek 2009, X-Men Movies...

This Challege could also be done effectively on Harry Potter, leading to a much more interesting, realistic and proactive main character 

In the universe Riddick comes from demons are very rare but the do exist, so when Riddick he is unprepared for them. After a furious battle the demons are able to capture Riddick and bring him back to their universe.

The New Watchers has sent Xander to a demon flea market to pick up supplies for Willow since Anya's willed him all her boons which allows him to walk through the market without harm. While there he catches a scent that seems to pull on what was left of the hyena in him. Following his nose, Xander comes upon the slave/pet section of the market where he witness a group of demons try to deal with a injured slave who was trying to escape. Xander watches as the demons are finally able to subdue the slave and gets him back into his cage.

Approaching one of the demons Xander learns that his slave has been a problem for them since he was captured. And that they're about ready to kill him and lose any profit they would have made by selling him then deal with him much longer since the demon doubts that anyone will buy him.

Since this slave is the source of the smell Xander followed, he decides in a fit of madness to buy him. The only thing he has to figure out is how to get his new slave to come with him.