I saw it twice, once we wiped totally but another time, the WHM and myself countered it and we finished it (bless WHM), me with sacred soil and her with the WHM skill Asylum (our healths the 3 standing went really really really low). It killed only who wasnt Inside those two (aka one BLM), we survived and finished the boss but yeah is a sort of enrage skill room wide attack, someone told me if you are being hit by 5 AOES it trickers that attack. Have yet to see the description for it. I can say, is not an insta wipe but maybe one healer alone may not be able to counter that, not sure. Our group was, two healer and two BLM and yep we finished the lvl 41-50no problem actually