Magic Armor

Twilight Princess
The Magic Armor is an item in Twilight Princess that Link can use to make himself invincible. With the lack of a magic bar in Twilight Princess, the Magic Armor drains rupees very quickly (about two per second). When attacked, it will drain 12 rupees. When you run out of rupees, the armor becomes very heavy, causing Link to move as if he has the Iron Boots equipped. If Link is out of rupees when he equips this, Link can not get on Epona, and if Link equips it while riding Epona, Epona will stop, and Link will be sent flying off of Epona. He also sinks in water if he runs out of rupees while swimming, forcing him to take the armor off or drown. The Magic Armor's design is similar to that of the crown and armor Princess Zelda wears, suggesting that the Royal Family had something to do with the making of the armor. Another possible connection to the Royal Family is the Triforce symbol near the bottom of the torso.

Where to find the Magic Armor
First, finish the Lakebed Temple and go to the Malo Mart shop in Kakariko Village, talk to the Goron elder standing outside the shop.

Then go inside the shop and donate 1000 rupees (it doesn't have to be all at once) to the Goron there to repair the bridge at the Eastern Gate of Hyrule Town. (Wii version: the Western Gate)

The Goron will say it is a glorious day and the bridge will be repaired.

Talk to the Goron outside to do a small minigame, which will reduce the price for a shop in Hyrule Town by 1800 rupees. (It would cost 2000 rupees without minigame, and 200 with, it is recommended to do this minigame)

You will start north of Kakariko Village, you'll have a big barrel of hot springwater on top of your head which you need to bring to the Goron at the Western gate of Hyrule Town. Just walk all the way there, without stopping to kill something, monsters aren't able to hit you if you keep the barrel on your head. Just try to evade everything on the ground, just walking further is the best thing to do. You can avoid all monsters by running along the East (West for the Wii version) edge of Hyrule Field to the bridge. When you are at the Goron at the Western gate, walk to him and he will tell you that he needs hot springwater. Lock him with L and throw it on him. If you hit him correctly, he will go to Kakariko Village at high speed and bring back a barrel of hot springwater, leaving a Heart Piece at the repaired bridge when he got back, take it and go back to Kakariko Village.

Pay the Goron inside of Malo Mart a small 200 rupees, or if you didn't do the minigame 2000 rupees. A shop is now opened in Hyrule Town, visit it and buy the Magic Armor for 598 rupees.

The Magic Armor is similar in appearance to the Red Mail from A Link to the Past.

The Wind Waker
In The Wind Waker, the Magic Armor appears as a kind of jewel or crystal (which somewhat resembles Din's Fire from Ocarina of Time). Upon use, a magical barrier will cover Link, protecting him from taking damage. The Magic Armor slowly drains Link's magic power while active, and will simply stop working once Link's magic meter runs out. Link can even activate the shield while riding the boat, giving him protection from attacks during overseas battles.

The Magic Armor is given to Link by Zunari on Windfall Island, after completing the Island Trading Sequence. It's an optional item in the game.

Trivia

 * In The Wind Waker, after you have finished the game and are wearing your normal island clothes for the second quest, the magic armor will still show the outline of Link's trademark hat even though he is not wearing it.