You need to have good skills and good materia to beat him. Also try getting the final weapons for everyone and all the final level 4 limit breaks. Have the accessorie "Ribbon" on at least one of your characters so they wont turn have stats problem and they can heal everyone. Have a lot of healing items and healing materia to cure your other members from stats problems and damage in there HP. He is not the hardest boss! After you get the hang of him try beating emerald weapon and ruby weapon! HAHAHAHAHA!! Then you will need a mirical and hope!