Found in the Elder Sanctum of The Ruins of Sescheron in Act Three. This cube allows players to gain an additional three legendary powers. The item can also be used to convert, breakdown and transmute Legendary Items, Crafting Materials and Gems.
The Cube can only be found in Adventure mode. There is no long quest or list of requirements to find it. Simply talk to Zoltun Kulle in Act town and then travel to the The Ruins of Sescheron in Act 3 and find the Elder Sanctum, somewhere on that map you will find the cube. Once found you can easily access the cube in any of the major Act towns at anytime.
Each recipe requires a certain amount of unique materials that can only be found from Horadric Caches or the Act 2 vendor Squirt the Peddler.
This recipe permanently destroys the legendary item and adds its orange text legendary power to the cube. If the legendary item has a range for it's unique effect, the highest possible value is the one chosen. The effect is stored in your cube and can be assigned to your character at any time by visiting the cube again. You can have a total of 3 additional legendary effects. One weapon, one armor and one jewelry effect.
Completely rerolls any legendary as if it had just dropped. Resets all stats for the items and gives new ones.
Turns a level 70 item into a random legendary of the same type. For example a One-Handed Sword has a chance of becoming Thunderfury Blessed Blade of the Windseeker.
Changes a set item into random part of the same set. The resulting item cannot be Ancient.
Removes an items level requirement and allows it be worn at any level.
Converts 9 gems into any other type of gem. All gems must be the same type and quality.
Converts 100 of any crafting material (White, Blue, Yellow) into type of crafting material you want. Death's Breath and Forgotten Souls cannot be created with this recipe.
Opens a portal to the "Not the Cow Level" special zone.
Opens a portal to the Goblin Vault.