You can draw those GFs from (SPOILER)Ultimecia's Guardians in her castle. You will go there once you defeat Adel.

The easiest way to defeat Adel is to first cast Meltdown on her, then cast Aura on any party members whose Limits hit one target. Like Irvine, Zell, or Quistis. If you have Quistis, then have her use her Homing Laser. Don't have Squall use Renzokuken, since some of his finishers hit all targets. Just have him use physical attacks. He should be doing pretty good damage if you have strong magic Junctioned to his Str. To keep Rinoa from dying cast Regen on her.