Forest of Remembrance

Follow the path and take out the undead by the bridge. As you reach the arching corridor, you'll find two skeleton brutes. Take them out as well. Continue forth and you'll eventually reach a door leading to another area. (The Pilgrim's Gauntlet) Enter it and clear it first before continuing. After getting the Void Key, continue forth in the Forest. Carefully cross the high bridge and take out the succubi along the way. Examine the tablet in the middle of the tower then continue downstairs.

Restore the riftstone if you have extra rift crystals. Continue to the second level underground. Kill the wolves outside. Take note that a minotaur may appear here as well. Be careful with dealing with this monster as a single misplaced swing from it can throw you off the cliff to your death. It will be helpful using the tower's window to go back and forth and keep yourself protected from its wild, powerful swings. The 2nd Level Underground also leads to the Black Abbey.

If you continue to the fourth level underground, that's where you'll find the gate that requires the void key. If you still haven't explored The Pilgrim's Gauntlet in the area's first floor, you should go back and retrieve the key. The door here leads to a deep dungeon called the Tower of Treasons Repaid.