Legendary Items
Legendary Items are purchased from the Overclock shop when certain conditions are met. They require a certain Overclock level, a Legendary Crystal in your inventory and a certain amount of Gigas & Crystals. Legendary Items are designed to have unique power-ups as opposed to typical stat power-ups, but some do still fill this niche. Only one Legendary Item can be equipped at a time, and they are usable in Sector only.
Legendary Item Shop
Here is a list of the current Legendary Items - keep in mind that they all cost one Legendary Crystal and a certain amount of Gigas & Crystals.