a very easy way to beat jenovas second form when aeris died is to give your best charecter a water ring which absorbs all of her attacks and thats a very easy way to beat jenovas second form.


jenova life: equip to your charecter a fire ring that nulfies fire attacks and equip fire(at least at level two) and elemental materia to a douple slot on your armor. but remember to bring echo screens because she uses silence which stops you from using magic and summons. if she silences you and you have no echo screens it will take a while to beat her because all you can use is normal attacks but who cares even if it takes awhile because she cant hurt you if you have all the stuff above equiped

and those are very easy ways to defeat the second and third forms of jenova.