Swords of Phantom Hourglass

There are two available swords in Phantom Hourglass: Oshus's Sword and the Phantom Sword.

Oshus's Sword
The first sword obtained in the game is Oshus's Sword, which is given to Link by Oshus. Link, truthfully, obtains this sword by himself in the cave next to Oshus' house. This beginning sword is not just avaliable for laziness, though; Link has to count all the palm trees on the beach where he washed ashore and write the number on the stone tablet next to the door in the cave.

Phantom Sword
The Phantom Sword is a special sword that can defeat Phantoms. Link gets this sword by defeating the three 'guardians' of the Pure Metals. The first metal, Crimsonine, is found in the Goron Temple with the help of Gongoron, after defeating Dongorongo. The second is Azurine, found in the Temple of Ice after defeating Gleeok and breaking the curse on the Yook. The final Pure Metal, Aquanine, is found in Mutoh's Temple. It was a sacred treasure kept in King Mutoh's Tomb.

Trivia

 * Unusually among swords in this series, despite having additional abilities that Oshus's Sword lacks, such as the ability to kill Phantoms, the Phantom Sword does no more damage to regular enemies than the sword it replaces. This may be because equipping Leaf as Link's Servant Spirit powers up his sword instead.