The old saying goes that lightsabres make everything better. Actually, I don't know if that's a saying at all, just something that makes sense, especially after viewing the above clip. It features the characters of Jaime Lannister and Eddard Stark from HBO's Game of Thrones, going at it in one of the season's crucial melees. Except they've traded in their Valyrian steel for frickin' laser beams.
The scene, which took place in the fifth episode of the first season, was rotoscoped in After Effects by YouTube user "Joel935M" a couple of days ago and posted on the video-sharing site. Other than the addition of the sabres and a relevant sounds, it's essentially the same fight with a bit of future added to the fantasy.
Goes without saying that if for whatever reason you haven't watched the episode yet (or read the books), the clip should be considered a spoiler.