Challenge description:
http://www.femlob.com/redir/ff10nsgnsno/

NOTE: I had to cut off the last ten seconds of this video to make it fit the YouTube time limit. The new Overdrive mode "Hero" that Rikku learns is evidence that Evrae is, by that point, defeated. All you're missing out on is his death animation, and I figured you could do without that for once. ;-)

I would discuss the strategy used in the video, but unfortunately Dailymotion's 1000 character description limit prevents me from doing so in full. If you're interested, read the description I posted alongside the YouTube version of this video here:

http://www.youtube.com/LukeGevaerts#p/c/227FB13063CBAA28/16/VT2qBVRuR_k