This is the hardest boss ever in history. if you don't agree post your hardest boss ever. and this is a place to talk about bosses and tips to defeat bosses.
Ruby weapon from FF7..You need to spend the entire game just to prepare to beat this boss...max out phoenix...max out final attack materia and have it joined in conjunction with Phoenix summon....max out mime two times and max Knight of the round...you need to get the w summon aswell so that you can double cast knights of the round(using this on one member and using mime on the others so that they all use the summon)...then whilst at it keep trying to use dazers on it so that it MIGHT be put to sleep so that it has less chance of knocking random members of the all lv100 party out of the fight whilst you spend god knows how long whittling away at it's massive 700,000-1,000,000 hp.