During your travels you may have come across the Centra Ruins standing ominously in the middle of the Centra Ruins. You’ll also be familiar with the area if you’ve already obtained the Tonberry Guardian Force by defeating King Tonberry. But the primary purpose behind the ruins is to obtain the optional “Guardian Force”, Odin.
Now Odin is not like any normal Guardian Force. You do not equip him to your characters and he cannot be summoned in battle.
Instead, Odin will show up during random battles as they are progressing and he will finish the enemy off for you. When he jumps in, much like when Angelo jumps in, the intended effect is a free attack and to end the battle more quickly and efficiently.
Unfortunately though, this may actually interfere with battles more than it helps. Read the warning below for more information.
Odin’s behaviour during the game can be quite detrimental. He will appear randomly for some battles and will cleave the enemies you are facing in half, instantly ending the battle. This means that you won’t be able to steal items, Draw magic, etc. and you also don’t get any AP or EXP once the fight is over.
Odin can be obtained late in the game, but there’s really only one thing you’ll miss out on by not getting him, which is that at the end of disc 3, during the final battle against Seifer, Odin is replaced by Gilgamesh during a neat cinematic that takes place during that fight.
All that said, its generally recommended that you not obtain Odin for these reasons. For those that choose to, read on for more information on how to get him out of the ruins…
Make sure to have Diablos learn 
Enc-None (which becomes available after it learns Enc-Half). Equipping this ability to one of your characters will allow you to travel through the Centra Ruins without engaging in random battles.
Having Enc-None is essentially a requirement for the Centra Ruins in order to reach Odin within the time limit. If Diablos has not learned Enc-None yet, consider using the Cactuar Island trick to get some quick AP. More details can be found below:
As soon as you enter the Centra Ruins a timer will start giving you 20:00 minutes to complete your mission and obtain Odin. Start by walking up the two sets of stairs.
Go through the doorway and stand on the platform at the top of the stairs. The platform functions as an elevator and will carry your team up to the next level.
This next level has a shrine with a ladder on the left and right side of it. Climb the ladder on the left side up to the next level.
As you get to the halfway mark, Squall will stop climbing, but there is another ladder that you can use to continue climbing even higher.
Walk into the structure and press the 
Button near the machines controls. The machine will light up blue when you have successfully activated it.
Now climb down both of the two ladders to the shrine and you will find that it is now lit up blue. Examine the blue orb and a set of stairs will reveal themselves to the right of the shrine. Climb the newly revealed stairs.
In the next area there will be a ladder on the left side of the screen. Use it to climb up a level and examine the eyes of the gargoyle statue (which currently has one red eye).
Choose to “take out the left eye” and then climb back down the ladder and head up to the next level.
Climb the ladder to the top of the dome and then examine the gargoyle at the top.
Choose to “put in the left eye” and the Gargoyle will reveal a 5-digit code. This code is unique to your game and you should write it down.
The code that the Gargoyle reveals is different every time you play the game, hence why this guide does not include screenshots of the actual code. Write down the code, otherwise you will have to back up to the gargoyle at the top of the dome to obtain the code again.
Pull out both the left and right eye and go back down to the gargoyle on the level below. Put both of the red eyes into the gargoyle statue and a prompt will appear on the right side of the screen asking for the code.
Enter the 5-digit code and then press the 
Button to exit the code entry screen. The door underneath the platform will open up. Its time to go insight and face Odin!
In Game Description: A legendary GF that sleeps in a dungeon. Zantetsuken cuts anything that stands in its way.
The boss battle against Odin is as easy as they come. Odin will not attack your party members in any way during the course of the battle. Instead, the idea is that you just have to bring him down before the 20:00 minute timer expires. He does have a fair amount of HP, but this should still be a relatively easy task if you were quick getting the code and getting the door unlocked.
Odin will join your team once you have successfully completed the mission. You will also get the 
Odin Card as a reward at the end of the fight.
Stop
Luck-J Scroll