There's a lot I love about this story, but it's going to be a bumpy ride for Lois, Clark, and reades unfamiliar with the Buffyverse - I took the same approach for a Stargate crossover a couple of years ago, beginning with that same mass grave; the characters at first assumed that it was a Jaffa invasion gone horribly wrong, and were wondering about replicators for a while before someone filled them in a little.
BTW, shouldn't the bodies be wearing chain mail?
TOC, if you want to post graphics into a comment it would help if you resized them first - I'm reading this on a 1024x768 screen and that Superman Returns picture is twice the screeen width, and screwing up the formatting of the text, everything's off the screen to the right.