According to the book, there is a sword Ragnarok for Tidus. You have to take a different sword and customize it to become Ragnarok. And don't be so sure the "Ultimate Weapons or Armor" are the best. I have Lulu's Minerva bangle, and trust me, it blows away anything you can find in the game. Break hit point limit, Break Mana point limit, auto Shell and auto Protect. The backup has Break hit point limit added to the Phantom Bangle, and the just in case has Poison proof, Death proof, Curse proof and Confuse proof. All these have different names and cannot be found in the game but must be created by customizing. Often the custom versions are better than the "ultimate" ones, but they are time consuming to "make". I would love to know what Ragnarok has for attributes, or what single attribute makes a sword Ragnarok to begin with.