Darksiders 2 Walkthrough Part 30 – Heart of the Mountain, Part 2
Head for the Passage heading Northeast. There are a few Corrupted Construct Warriors who will attack Death but nothing too big or major. With Karn's help they will go down very quickly. In the passage you will also be attacked by 5 more Tainted Construct Warriors. Take them out quickly and then follow the passage to its Eastern end.
In this massive room, take a little time to smash the crates and barrels. After that head for the Eastern Wall. Karn will once again offer to throw Death up to the ledge. Move along the ledge carefully to the opposite side of the landing site to claim a chest. Once you have that just jump into the pool below and start swimming down. Turn to the North as you and hug the bottom of the pool. There you will find another of the Boatman's Coins. Continue to the North and surface. Turn to the West and climb up the wall there. Head forward and go around the Orb to the other side of the room. You need to continue West then dive into the pool of water. Head to the Northwest and surface nearby the chest. You will find some hand holds to the South. Climb up them and then turn to the West to find the chest. You can now either dive back into the water or trigger the pressure plate then roll off it into the water below. Dive back down and head to the East through the hole in the wall. Continue going as far East as you can. After that just climb up the wall and step onto the pressure plate there.
Time for some fun work. Karn will stand underneath the door and hold it open. Death needs to roll forward to get to the Orb in front of him. Roll it straight across the room. There you will see a Wall Ball Socket. Line up the Orb with the runes on the floor and shove it forward (or just roll it up into the socket it) to get it in. This will raise the elevator from the water with the Golem but it also summons roughly a dozen Tainted Constructs, a mix of both Warriors and Adjuncts.
After the fight head for the Northwestern corner. Aim and smash the Corruption Crystals there. After that just climb up, smash the various items about then claim the chest there. Next turn to the Southwestern passage and head through there. Opposed to continuing to the Southwest, turn to the Northwest. From there just continue to the West until you arrive in the room filled with Lava.
Move the Golem into the Ball socket on the ledge and fire the chain across the room. Cross the chain until you arrive at the vine patch to the South. Jump over to that then climb up. Lean from the wall and jump over to the pillar that is sticking down from the ceiling. Spin to the opposite side then jump to the next one. Repeat and jump over to the beam coming out from the next ledge. Head on toward the door in front of you and over to the next room.
In this room it is time for some Wall Running. Jump from the first wall to the second to reach the hand hold you need to continue. Get to the end of the hand hold but move carefully. You need to go from this one to the next ledge between the flows of molten stone. Wait for the flow to stop then immediately begin the wall run. You will make it with a little time to spare. Now head on to the South and into the next room.
A number of Tainted Construct Warriors are there to attack Death. They are just the start though. Once those 5 go down there is a Tainted Construct Champion waiting in the wing. It is stronger and more durable than other Champions you have taken on before. Still, keep with the horizontal style of dodging and it is very simple to avoid his attacks. If Death gets low on health and some access to his Reaper form, this is not a bad time to use it. The fight will end quickly either way. Take out any remaining boxes, barrels and vases then go off to the South. You will find the Skeleton Key that has been missing in the ornate chest to the East.