i've killed it many many times since 97
stuff that can be used - big guard (barrier/mbarrier/haste), regen ring, knights of the round (especially if you have w-summon and character/s with mime), sneak attack (paired with knights), final attack (paired with phoenix)
you can equip a 9999 hp character with 2 materias -> emerald uses aire tam storm which does 1111 damage for each materia on the character -> character goes lucky 7s
discovered this back in the day
combine that with knights and that's it
also omnislash
to beef up your characters you can spend some time in gelnika and morph enemies into sources that permanently increase stats