Crimson Desert Sanctum of Mortification – How to Restore the Power Device

TL;DR

• This puzzle is part of Chapter 9’s Fragments of Darkness main quest in the Byron Estate, Demeniss.
• The orange search area on your map is misleading — both items are outside it, to the north.
• You need two items: Fusion Reactor Core: XXIII-IV (down the spiral stairs) and Fusion Reactor Core: VIII (behind vines, through the grate).
• Use Axiom Force to carry them, Kuku Pot to seal and transport them, and Jump + Force Palm to lock them into place.
• Completing this triggers the Pursuit Beyond the Veil quest and counts toward the Sanctum Exploration Challenge.

The Sanctum of Mortification is inside the Byron Estate in Demeniss, and it becomes accessible during Story Chapter 9 as part of the Fragments of Darkness main quest — mission 131 in the game. You can’t complete it before the quest triggers, so if you’re here early trying to knock out Exploration Challenges, you’ll have to come back.

Once you’re here, the objective reads “restore the power device.” The game gives you almost no guidance on how to do that. On top of that, the orange search area the game marks on the map points you in the wrong direction — the objects you actually need are sitting outside that zone entirely. Once you know where to look, the whole thing takes under 10 minutes.

For context on other sanctum puzzles, we have guides on the Sanctum of Revelation, Sanctum of Renunciation, Sanctum of Expiation, and many more.

Where Is the Sanctum of Mortification in Crimson Desert?

The Sanctum of Mortification is found northwest of the Golden Plains in Demeniss, within the Byron Estate. You’ll reach it naturally through the Fragments of Darkness main questline after finishing the Cloister of Enlightenment mission.

Before You Start — Key Mechanics to Know

This puzzle relies heavily on tools you may have only recently unlocked. Here’s what you’ll be using:

Axiom Force — Hold L3 (PS) / TAB (PC) to grab and carry heavy objects. Without this, you cannot move the Reactor Cores. See our Axiom Force guide if you need a refresher.

Kuku Pot — The only way to transport Reactor Cores across gaps. You Seal items into it and Discard them back out at the destination.

Blinding Flash / Concentrating Light — L1+R1 then hold L1 (PS) / LB+RB then hold LB (Xbox) / CTRL+Left Click then CTRL (PC). Used to burn vines blocking the second core. See our Blinding Flash guide for full details.

Minimap tip: If an icon is white, you are on the same level. If it is faded, the item is either above or below you — like the core down the spiral stairs.

Lost your Kuku Pot? Check the Lost & Found chest at the Howling Hill Greymane Camp behind the Provisions Keeper. If it’s not there, do the Mission Dispatch at your camp called “Kuku Pot Production” to make another one.

How to Restore the Power at the Sanctum of Mortification

There are two Fusion Reactor Cores to find and slot. Both are in the north section of the Sanctum — ignore the orange search area the game marks, it’s wrong.

Part 1 – Obtain and Place the Fusion Reactor Core: XXIII-IV

This core is inside a ruined building to the north. There will be Hexe Earthen Soldiers guarding the area. You can fight them or try to slip past — either works.

1. Head north inside the Sanctum until you see two icons on your minimap.
2. The entrance to the building is a smashed-open wall. Climb or glide in through it.
3. Head down the spiral stairs inside. The core is at the bottom — its minimap icon will appear faded until you descend to the same level.
4. Use Axiom Force (hold L3 / TAB) to grab the Fusion Reactor Core: XXIII-IV.
5. Press Triangle (PS) / Y (Xbox) / R (PC) to Seal it into the Kuku Pot.
6. Return to the power device. You’ll see a pillar with a missing dome on top.
7. Open your inventory, enter the Kuku Pot, and select “Discard” on the Fusion Reactor Core: XXIII-IV to drop it out.
8. Use Axiom Force to push it onto the base of the pillar.
9. Climb up the pillar, then use Jump + Force Palm (jump then R3 in air) to slam the dome into place. This Jump + Force Palm move is used frequently in later stages of the game to lock environmental triggers high up on walls or pillars.

Part 2 – Obtain and Place the Fusion Reactor Core: VIII

Go back to the same northern building where you found the first core.

1. Look at the back wall of the building — you’ll see vines and shrubs covering it.
2. Use Blinding Flash / Concentrating Light to burn the vines away.
3. Behind the vines is a grate. The Fusion Reactor Core: VIII is behind those bars. It’s small and easy to miss — use Axiom Force to pull it through the grate toward you.
4. Press Triangle / Y / R to Seal it into the Kuku Pot.
5. Return to the power device. Look at the center of the machine — one side has an empty battery slot.
6. Open your inventory, enter the Kuku Pot, and Discard the Fusion Reactor Core: VIII to drop it out.
7. Slot the core into the empty battery slot using Axiom Force, then use Force Palm to push it firmly into place.

What Happens After You Restore the Power?

Once both cores are slotted correctly, the power device activates. A cutscene plays — and it is not skippable on first viewing, so let it run.

After the cutscene, you’ll be given the Pursuit Beyond the Veil quest, which kicks off the next section of Chapter 9. The Sanctum also remains accessible after completion if you want to revisit. Finishing this puzzle counts toward the Exploration Challenge tied to this location.

Sanctum of Mortification — Common Issues and Fixes

“I can’t find the Seal prompt.” Make sure you’re holding Axiom Force first (L3 / TAB) so you’re actively gripping the item. The Seal prompt (Triangle / Y / R) only appears once you have the item in your grasp.

“The items aren’t in the orange search area.” That’s correct. Ignore the orange marker — both cores are north of it, in and around the ruined building.

“The core fell off the pillar before I could lock it.” Keep the Kuku Pot approach in mind — discard the item close to the pillar base so it doesn’t roll away, then use Axiom Force to guide it before climbing up to lock it.

“I lost my Kuku Pot.” Check the Lost & Found chest at Howling Hill Greymane Camp. If it’s not there, dispatch the “Kuku Pot Production” mission at your camp to craft a new one.

More Crimson Desert Sanctum and Quest Guides

• Sanctum of Atonement puzzle guide
• Sanctum of Deliverance puzzle guide
• Sanctum of Solace puzzle solution
• Sanctum of Exaltation puzzle solution
• Sanctum of Temperance puzzle solution
• How to ring the bell in Demeniss
• How to use Axiom Force
• How to reinforce equipment in Crimson Desert
• All main story quests and chapters
• Crimson Desert full review

Where to Get Crimson Desert

Crimson Desert is available on PlayStation, Xbox, Steam, and Epic Games. Visit the official Crimson Desert website for more details.