The Rudol Gem is an item that only appears in Fire Emblem: Radiant Dawn and raises Defense by 10 when equipped. It is given to Empress Sanaki by Sephiran in Part IV of Radiant Dawn when he either dies or joins you. It can only be used by Sanaki, and would work very well for her because she has low defense growths, being a magic user; however, it comes to her in the very last level of the game, where there are only magic users to be fought.