SideQuest - Find and Kill Gorewood
Gorewood is found in the depths of the Weeping Crag. (You'll need the Voidwalker to access the portal glyphs here) Fast-travel there and go past the bridge. Look up to find a Stone of Mystics (7)
Climb the ledge to the left and ignore the skeleton door for now. Wall-run to the right then drop down to the hand-hold below. Wall-run again to the right and to the next posts then climb up to get inside the dungeon.
Destroy the enemies then enter the door to the west. Destroy another construct there as well as the debris. Loot the chest then go through the nook to drop down to the lower ledge. There's another chest waiting for you there.
Jump to the water and get the Boatman Coin under the drawbridge if you haven't done so yet. Return to the ledge where the skeleton door is then wall-run to the second hand-hold. Drop down and quickly use deathgrip to grab to the hoops and reach the chest in the other end.
Return to the second floor and make your way further inside to find a pressure plate. Step on it and wait for the platform to fully raise. Now quickly wall-run to reach the upper ledge. Ignore the circle for now then proceed
Go downstairs south then wall-run twice past the corner to reach a chest containing the Skeleton Key. This should open the nearby door as well. Before leaving, head to the left of the door then perform a vertical wall-climb. Do a cornering wall-run again to reach another chest in the ledge to the west.
Exit through the door and this will take you back to the balcony. Exit to the skeleton door and open it using the key you acquired. Head inside, defeat the stalker and loot the two chests.
Drop down and continue along the narrow corridor. Before going underwater, perform a wall-bounce the reach the hand-hold. You should see a Book of the Dead page (10) in the far end of the corridor. Keep wall-running and bouncing until you get it.
Dive underwater and follow the path until you reach the end of the submerged tunnel. Follow the path until you reach a wide area. You can find Gorewood here.
Gorewood's attacks are slow and easy to evade. Just evade and counterattack whenever you have the chance. Refer to the video below for the actual battle.
After the battle, look up to find a Stone of Power to the east. Return to Thane to get your reward and complete the quest.
(After getting the Voidwalker)
Head to the upper balcony (not through the skeleton key door) and head north. You should find an overhead portal and another one to the west. Activate them both then enter the portal and continue to the north to find a treasure trove. Loot the chests and destroy the objects then head north and dive to the water there. Swim south to find GnoMAD's gnome before the waterfall.
Jump down to the southern pool and swim to the northwest. Climb the wall to reach another Boatman Coin.