Guardian Forces
Quezacotl
Shiva
Ifrit
Siren
Brothers
Diablos
Carbuncle
Leviathan
Pandemona
Cerberus
Alexander
Doomtrain
Bahamut
Jumbo Cactuar
Tonberry King
Eden
Guardian Forces
From Final Fantasy II to Final Fantasy VII, summoned creatures have always been there to lend a helping hand in the heat of battle.  Final Fantasy VIII has pushed the summoned creature's role even further with the introduction of Guardian Forces.  They're still the same powerful creatures you've come to know and love, and you'll see a lot of familiar faces, but this time their role is much larger than it has been in the past.

Rather than just assisting in battle, Guardian Forces actually determine the vital stats and abilities of the character they're Junctioned with.  Face it, without a GF backing him up, Squall is pretty much an ordinary guy thrown into an extraordinary circumstance.  Granted GFs don't do it all on their own, but they're the basis on which a character is built upon.

Junctioning with a GF
Junctioning may sound complicated at first, however, it's really quite simple.  Open the Main menu and select the Junction option, and then select a caracter.  At first, only the Junction option will be highlighted, because a GF must be Junctioned to a character before the other options become available.

Choose to Junction and select the GF option.  A list of all the GFs you've had join you thus far will be shown.  Those in white are available for Junctioning.  Grayed out GFs are already Junctioned to teh characcter you've chosen.  GFs cannot be selected until they have been removed from the character they're currently Junctioned to.

After selecting a GF, back out of the screen using the Triangle button.  You must next Junction magic to your character's stats using the GF;s Junction abilities, assuming that Junction stocked magic to teh stat.  Different types of magic have different effects on the various stats.  You don't have to Junction magic yourself.  If you want, you can select the Auto option, and then choose to have the game pioritize increasing a character's Attack Power (Atk), Magic Power (Mag), or Defense (Def).  The game will then automatically choose from the character's stocked magic, and make appropriate Junctions based on what you've chosen.

GF Growth
GFs grow throughout the game in a way that's very similar to your own characters.  Just as your characters gain experience and go up levels, so do your GFs.  Any GFs Junctioned to characters in a battle receive an amount of experience equal to what the character they've Junctioned to receives.  However, if more than one GF is equipped on a character, the experience gets divided into equal shares between the GFs.

Besides Exp (Experience Points), GFs also gain AP (Ability Points).  AP is earned to teach GFs new abilities and comes in much smaller portions than EXp. AP is earned after any battle during which a GF was Junctioned to a character in the battle.  If more than one GF is Junctioned to a character, the GF's still receive the full APamount rather than having to split it amoung them equally.