One of the Scoobies takes the Were vaccine. But it goes wrong they end up infected.

The level of crossover is up to you, but there must NOT be any dimension jumping involved.

Can be any season or Scooby.

But not Oz, he should be the one that helps them though the change.

The Scooby can absolutely NOT be submissive! (Beta fine, but not submissive)

Can be Slash of Fem-slash if you have to, but I would prefer it not to be.

If using Xander, don't make him a Hyena. Making him a Pan-were because of the possession is acceptable.

A Ri...

What if Xander died and is reincarnated as a X5.

Musts:

Canon until after S7 BtVS.
Xander must remember some or all of his past life, how and why is up to you.
Xander being found or adopted by one of the Scoobies.

Optional:

Xander being Max's twin.
The Pulse
Xander being the 'son' of one of the slayers.

Have fun!

Some how Xander ends up in the Anitaverse. Wish/portal/spell it's up to you, as is when in the Buffy series and the Anita books it is set.

However instead of joining up with Anita and co. he ends up joining Human First.

Then ends up being turned or bitten...

Be creative and have fun with this.

I found season six disappointing, the Trio just didn't hit the spot as the Big Bad.
So the challenge is to add a bit of spice to the events of season 6.

When the portal was open something came though.

Personal favourites: The Borg or the Zerg.

Must conform with beginning of season six, e.g: Buffy's resurrection.
Must include magic addiction for Willow.

Points if the Trio are included and end up joining forces with the scobbie gang to fight the Big Bad.
Points if Xander is part of the Big Bad, but in a big way, like the Overmind for the Zerg e...