it's halo reach, community montage, edited in black and white, it's under 5 minutes long, one of the first few clips was a dmr/snipes ffa on sanctuary from the base, it was sort of a farewell tribute to reach when h4 came out.
it used a really mellow edm song. for some reason blizzard remix is coming to mind and the word "eyes".
I forgot the name obviously but it's one of my favorite edits, if anyone knows it please post, thanks