What is the special battle in the Gold Saucers Battle Square?
You can enter this in Disc 2 after you get Cloud back in your party. Go to the Battle Square and earn enough BP to get the W-Summon materia and Cloud’s Limit Break Manual (use it so that you have all seven limit breaks). Then go and kill the Ultima Weapon, get the Ultimate Weapon. Now, return to the gold Saucer and Dio will sponsor a special battle for you. You’ll have to fight against many tough enemies (mostly bosses). Win the battles and you’ll get lots of rare items, including the Cat’s Bell, the Gambler, and so on. The easiest way to win the special battle is to Mime something powerful or useful like a healing spell or Knights of the Round, so that even if you lose use of your magic or summon materia, you’ll still be in the clear.