I beat that damn thing before, but I didn't save. Now, for some reason, I can't beat it again. The first one I can beat with no problem -- it doesn't even get a para-flare off. The second one, however, is the problem. It's para-flare will paralize my entire party, then the match is over. I have no idea how I was able to beat it the first time. What should I do to beat this damn thing?

Make sure you give the yellow band to Jansen, and make your immortals learn it also. Then you won't get paralyzed. Did you find the yellow band? If not, you're fucked.

 I don't have a yellow band. Where do I get it?

LOL. After you leave the Grand Staff Construction base, you go to the eastern shore, there is a save point there. Then you go over the bridge over water to a beach like place. Once you pass that area, you are in the reef shallows. The yellow band is in one of the clams//chests in there.