Also, it's quite possible to beat the weapons without it.
It's quite well known that Ruby cannot wipe you out in one attack at 9999 HP + Ribbon, while for Emerald, Aire Tam Storm poses a danger - however, the less materia you equip on a character, the less damage it will do to them. While to a character with 9 or more materia, it will do 9999 damage, to a character with two materia, it will do 2222, and a character with none, it will miss. (However, Emerald's other attacks are still very deadly)