Epic rarity (Purple) versions of the Fire Oni Mask and the Void Oni Mask can be found when looting standard and Rare Chests ...

Now that we have that out of the way, we present you wallpaper of Oni-Link -- the almighty character hidden somewhere within Majora's Mask. Plaster this image all over your desktop and drool at ...

If you go this route, you will be able to find the purple epic versions of the masks. If you can find a legendary treasure chest, you increase your chances of finding an Oni Mask exponentially.