It's dangerous to go alone, take this?

The Legend of Zelda series loves the whole "get item, progress in game" deal. Its a formula that has been prominent ever since its original title - although it might not be as poignant as it is in later ones. (They mostly followed a "get the item, use it immediately in the dungeon to progress, remember you have it, cause you'll need it later"). The acquisition of these items, in turn, can change play styles as well as open new areas that couldn't be previously accessed. For example, in Majora's Mask, once the player acquire's the Goron Mask, walking pretty much becomes obsolete. The roll is way faster and doesn't cost magic, giving it favor for traversing across the land.

Weeeeeeeee.

Above image taken from https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4YhNjBdDNVIgePK-jz-mz-6O8hOoPer4zG1RGUZFrXSIezPzC9uk_Owfv45Z_wiLt7v5uaF71HxOMb84HrAz5E6t1Fp6euX6p9KXC1SLmR0mIV7C5zjF8YB_fc1tb8We-nxYYfj3kOQ30/s1600/goht+boss+fight+majora's+mask+goron+roll.jpg

But wouldn't it be great if you could put your own item in the game? I know it would. If I could mod LoZ, I would. (Mind you, you CAN, but its a long and laborious process of love that I don't quite have time for...) Since we were talking about Majora's Mask, let's design a new item for the game. (Fun fact: second choice was A Link to the Past). With Majora's Mask being about, well, masks, I would probably add an item to the game called the Doppleganger Mask. I shant bore you with details of what it would look like, but I will say what it would bring to the table in terms of game play and how it would change the dynamic of Majora's Mask.

Like this, but picture Link.

Above image taken from http://www.newlaunches.com/wp-content/uploads/2013/01/Doppelganger-Face-Masks-2-thumb-450x506.jpg

With so many masks in Majora's, I don't think the dynamic of the game would be thrown off at all. If anything, it would add more puzzles and annoying Heart Pieces to collect. The mask would work like this - once worn, a second Link would appear next to the original link. At the same time, there's a magical "barrier" that goes between the two and runs parallel. As the player moves, the second link copies the motions in a mirrored fashion, e.g. if Link walks forward, so does 2nd Link. If Link moves to the right, 2nd Link moves to the left, etc. However, if Link crosses over past the "barrier," then the 2nd Link vanishes. Additionally, by pressing A while wearing the mask, Link can switch positions with his Doppelganger. The Doppelganger also copies any items used (if Link shoots an arrow, 2nd Link will shoot one in the same direction from wherever he is standing). Both are affected by collision as well, e.g. if 2nd Link can't move in the specified direction due to a building, crate, etc., neither can Link and vice versa.

With something this expansive, it would most likely be restricted in open areas like Great Bay, and the field surrounding the main. Where it could find its niche is in dungeons or those cool holes in the ground you find by blowing up rocks. Here are just a few examples of what could be accomplished:

1. Let's say that there is a path ahead that branches and reconvenes at intervals. (One path splits to two paths, then those two have different paths, but come back together, etc.) Most paths at one point have a gap. You notice that where there is no gap on one side, there is on the other. What do you do? Bust out your sweet Doppleganger Mask, of course! Since both Links are linked (badoom, chhhhh), the Link with the path will allow the other Link to walk over the pathless part. You could then switch as necessary until you have traversed the path.
2. There's a bunch of enemies in the room. Solution? Use the Mask - two Links are better than one! (Although you would take the damage from both Links... so be careful, I guess).
3. There are two of those Eyeball switches at the end of a room. Shooting one and then the other has proved useless as the first one shot opens before the second one can be shot. What to do... Oh right, use your DOPPELGANGER MASK. (I'm enjoying that). Since both Links will shoot, all you need to do is stand in front of it and fire away.

These are just a few examples of how this mask could work. Since the game is all about masks, I feel it could be added without detracting from the rest of the game play, as well as offering unique was to combat certain situations.