I actually do not write Highlander fics since I have only seen the movies. (I liked one and two...number three was just a remake, and I am still angry at them for killing of Conner McCloud in the fourth)

But, I do though, in my Angel fics, more often than not, borrow the whole immortality thing.

So, most of the time my stories will by about the series Angel. In some cases, there will be a few Buffy stories, but for the most part...The characters will be crossing over with Angel people.