It has the same basic purpose as the Master Sword, to banish evil away.
In The Legend of Zelda: Oracle of Seasons, Link finds the Noble Sword deep in the Lost Woods. In The Legend of Zelda: Oracle of Ages, the sword can be gained by completing the trade sequence or via a password.
In the Japanese versions, the Noble sword is named the White Sword.
 Oracle of Ages
You recieve this sword by completing the Trading Sequence. It is more powerful than the Wooden Sword and allows you to shoot beams from the blade at enemies when you are at full health.
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