I never realized it had to do with ARMOR. I recall that in the FAQs I had, you needed all 108 stars before taking on Rockaxe and when given the chance between "Nanami!" and "Look Out!" you had a half second to pick one. You NEEDED to make a decision and hit the button before the game took the choice away from you. And THAT, so says the FAQ, is what will save her. I played the game two or three times and I always did it that way and I always saved her. Of course, I never stripped her of armor either...