Hunted Demons Forge

From the main menu choose the Crucible Map Creator can then choose Create. Once the creator loads up press A then B. The square you were just on should have the Start button on it, signifying that its where the level starts. Then press start and choose save map. You will then have to choose up to six words for the name of your level. Once you have your name press start and it will be saved and you will earn your achievement