
Odin
Odin is not a normal GF, in that he may not be Junctioned, nor may he be directly summoned in battle. It's not even possible to tell by sight whether or not he has joined the party. Instead, he is a lone spirit who acts of his own accord. After defeating him in battle at the Centra Ruins, he will acknowledge your strength for the future. From then on, at the start of any battle, he has a small chance of appearing and bringing it to a quick conclusion before the party is able to act.
Notice: Although Odin may be recruited at any time, he must be acquired before the end of disc 3 in order to find Gilgamesh. When Gilgamesh appears in the final battle of the disc, he replaces Odin. It is not possible to find Gilgamesh in disc 4.
Attack
Zantetsuken
A stormcloud gathers overhead, its rain soaking the battlefield. A hoof splashes ominously in a small puddle before we cut to its rider Odin, his breath condensing in the air. After a second surveying the scene, lightning strikes to signal his attack. His horse rears, leaping towards the enemy party as Odin strikes three times with his fearsome sword. Each hit is accompanied by a flash and the bloody afterimage of one of the characters of "zantetsuken." Odin's face lingers in the foreground for a moment before fading away, as the enemies, now cleaved in two, slide apart.
Duration: 0:20
Movie (AVI, DivX, 1.64MB)
Location
Visit the Centra Ruins, the unusual crystal-shaped structure on the Centra continent, to be issued his challenge. From the time you enter, you have twenty minutes to make your way to Odin's lair and defeat him in battle; That includes the time you spend fighting, so Enc-Half or Enc-None are highly recommended. Take the gem from the eye of the statue on the way to the summit, and use it at the top to obtain a five-digit code number. Take both gems back to the first statue and use the number to find and confront Odin. He will not attack until the 20:00 time limit is up, at which point he'll zantetsuken the party. So hurry up.

