i see some people have trouble taking down emerald and ruby wpn from ff7, i will give you my guide to utterly annilating these foes.
EMerald is 100x harder then ruby ruby is actually insanely easy.
EMerald wpn walkthrough: The underwater materia isnt really needed. You will need the followin materia Knights of the round, mime, W summon, Final attack, life and or pheonix materia. For this tactic come in with everyone having their limit break (preferably cloud, tifa, and a random other person with a multiple hit limit break) open up with limit break/w summon Kotr whichever happens first. mne it and after about 10 or so kotr he will drop.
Emerald wpn walkthrough melee combat only. ive managed to take down this beast with no offensive magic. I just used 4x cut on all my characters and came in with their limits and used them when they came up. Final attack, double cut. haste etc etc are all needed for this. I reconmend Cloud, tifa, and cid if you want to use this tactic. randomly throw out a mega elixir if you get hurt you will see he has nothing on your party and you will grind him down.
Ruby wpn- after takin down emerald wpn this guy is a joke. just do the following link the following Master summon <-> Mp absorb Kotr <-> hp absorb Final attack <-> life and a w summon.
Just cast kotr 2 times he will hit you back with ultima but the thing is after you cast kotr, you will get back all of your hp/mp back due to the absorb materias. he literally cant touch you with this method
i would like to add that in mission 50 super gold sol badguy is Porbably the hardest boss ever. (for ps2 version of guilty gear xx)