Light Arrow

The Light Arrow gives Link's bow the Power of Light. Each arrow uses Magic Power.

Ocarina of Time
In Ocarina of Time, Princess Zelda will entrust you with the Light Arrows in the Temple of Time. They are needed to defeat the King of Evil, Ganon. An added bonus is the almost guaranteed side effect of any enemy killed by them dropping fifty Rupees.

Majora's Mask
In Majora's Mask, they are found in Stone Tower Temple. They are used to invert Stone Tower Temple in order to continue through the dungeon.

The Wind Waker
In The Wind Waker, Link finds them in Ganon's Tower by fighting Phantom Ganon. They are used to defeat Ganon. They are the ultimate weapon in the game; it performs a one-hit kill, which can even defeat Phantom Ganon and Darknuts.

The Minish Cap
In The Minish Cap, they are achieved after a few steps in a mini-quest, and are optional. Kinstone fuse with someone who looks like he's not from around here in a house in western Hyrule Town early in the game. Go to the newly opened portal, and use the Gust Jar to suck in the ghost circling the old man. Return later in the game, and talk to the man. You'll get the Light Arrows then. If Light Arrows aren't charged, they will act as normal arrows.

Twilight Princess
In Twilight Princess, you cannot actually obtain the light arrows. However, they do make an appearance. In the battle on horseback with Ganondorf, Princess Zelda will fire Light Arrows at him to slow him down, and then you can attack him.