You use these beauties to get special orbs from an NPC in Jeuno. These orbs let you enter special level capped (20-60) battlefields marked by "burning circles" and fight special "Notorious Monsters."
These BCNM's are the source of some of the most sought after items and spells in the game. There are BCNM 20's (level 20 capped) fights that drop the coveted Astral Ring, a level 10 ring that converts 25 HP to MP. These rings sell at AH for 5 million.
Similar items, valued at several hundred thousand to millions, drop from other BCNM's.
So, save 'em
