Return to the Forge Lands and talk to Alya | The Tears of the Mountain Darksiders 2 Guide
Last update: 11 May 2016
Open the world map and select [Forge Lands] (the above screen), located south of [Tri-Stone] (you can just as easily fast travel to Tri-Stone and reach the forges on your own from there - the choice is yours). Once you're there, approach the central area to trigger a cutscene. The game will automatically unlock a new main quest called [To Move a Mountain]. As for the rewards for the current one, those are: 750 XP, 3600 gold, the Maker's Key (used for activating Constructs) and Reaper Form (an offensive skill which lets you transform into a Reaper).
[TIP: Acquiring the Maker's Key means you can now go to new locations. It's doesn't make any difference if you've only been completing main quests so far, but it's worth knowing if you've tried exploring optional dungeons.]
[TIP: Reaper Form is an attack activated by the V button, although it's only available after accumulating a predetermined level of Reaper Energy (shown by a flashing icon in the top left corner of the screen). After shifting into the Reaper Form, the character becomes immortal for a few seconds and deals a huge amount of damage, so it's better to save this ability for harder battles, even more so considering that building up the required amount of energy takes up a lot of time.]