Buffy the vampire slayer/ the vampire diaries.
Plot: Xander is chosen by Qetsiyah to become a hunter.
Rules: Qetsiyah must appear before Xander in either season 2 or 3 she must tell him what he is and why his powers were created. She must also train him to kill Sylis and become the greatest vampire hunter he can be.
This story should have major character death it it, Buffy and Giles should be killed off by either Angel, the mayor, Faith, or some demon looking to make a name for himself. Willow can either survive as a cripple or killed, Cordelia and Oz can escape and move on with their lives or be killed by someone or something. (As a twist of irony Cordelia can be killed by a mugger and Oz killed by a werewolf hunter.)
With the Scooby gang dead Xander must leave the hellmouth take a five year training trip and then head to mystic falls a couple of years before season one of the vampire diaries start.
This story can be either a harem or just one girl with him, if you do go the harem route these are the girls that Xander should be with. (Qetsiyah, Bonnie, Caroline, and anyone else you want.)
Forbidden: Xander being killed off.
Damon and Stefan or any other vampire being allowed to live by Xander unless it's part of some plan.
Powers Xander should have: resistance to being compelled.
Medium resistance to magic. (Meaning only high level spells can hurt him.)
The more vampires that he kills the stronger and faster he becomes.
Heightened senses and healing.
The ability to use magic but only as an average witch or male witch.
You can add any other powers that you want.