What is a Guardian Force?: A Guardian Force is just like a summon spell from Final Fantasy VII, and previous Final Fantasy's. For those of you new to Final Fantasy, a Guardian Force, or Summon, is a magical monster you call on to hurt the enemy or to heal your party. Of course, just like any other magic spell, the more you use them, the more powerful they get, and according to their attributes, they make you stronger, more agile, ect. The farther they are in the game, the more powerful they are, such as Eden. I'm assuming that Eden is very hard to get, just like Knights of the Round in FFVII.

How do you get them?: The system for acquiring these is much different than in FF7 and FF6. In order to earn the monster's respect, you must defeat them, and then you can call on them for their power (just like Leviathan and Asura from FF2(U.S.)). There is no more materia, so they just get more powerful as you use them, I dont know if they have levels though.
Alexander
Bahamut
Description: Alexander towers over a far off mountain range, and inches up to the edge of his canyon. He then open his monsterous shoulder lasers, and lets it rip. Lasers come out of the sky, making a very nice looking semi-nuclear explosion. Description: As Bahamut soars through the clouds, he peaks his head above the clouds, and ducks back down. The clouds bend to his will, and lightning shoots out of them as he bursts down, opening his wings. He shoots a few small shots, and then charges for a big one. He shoots it, very big explosion.
Brothers
Cactrot
Description: Description:
Carbuncle
Cerberus
Description: Description:
Diablos
Eden
Description: Description:
Ghoulish
Ifrit
Description: Description:
Leviathan
Master Tonberry
Description: Description:
Pandemonium
Quetzalcoatl
Description: Description:
Shiva
Siren
Description: Description: