Ragnarok is an esper, not to be confused with the sword of the same name, even though the magicite can be used to make either. It is obtained in the weapon shop in Narshe in the World of Ruin. Locke is needed to access the shop.
The owner in the back offers to hand over the magicite or refine it into the sword. If the player chooses the magicite, its summon, Metamorphose (Metamorph in the original version), transforms an enemy into an item. Its Hit Rate is dependent upon the target, and is not affected by the Vanish-Doom Bug. It costs 6 MP to summon, and teaches Ultima at a rate of X1.
Since Ragnarok is the only esper to teach Ultima, many players take the esper instead of the sword, but if one has enough patience to remove the curse from the Cursed Shield, they receive the Paladin Shield, which can teach Ultima at the same rate. This allows players to take the sword instead of the esper, which they can then trade at the Dragon's Neck Coliseum for the Lightbringer, the game's ultimate weapon.
Ragnarok is one of the five Promo cards. In the Japanese and American versions, he must be downloaded from a download station. In the European version, the player simply has to enter the code , , , , , on the Download Pop-Up Card screen.