Mortal Shell 2: How to Cleanse the Pulsing Caves Beacon

The Pulsing Caves Beacon sits inside the Sanguine Caverns region, and interacting with it opens a challenge dungeon set in the Mawbreak Cavern. Cleansing it clears the corruption, sets a fresh respawn point, and hands you an Ovum needed for campaign progress. The route is short but packed with flying and ground enemies, plus one optional pickup worth grabbing on the way through.

Quick answer: Select “Cleanse Beacon” at the Pulsing Caves Beacon, fight through the Mawbreak Cavern to the end, use “Cleanse Corruption” on the corrupted structure, then collect the Ovum to teleport back to the now-cleansed Beacon.

What cleansing the Pulsing Caves Beacon gives you

Cleansing this Beacon does two things. It removes the darkened overgrowth that blocks the extra menu options, and it rewards an Ovum at the end of the run. Ova are the currency the Undermether needs from you, so every cleansed Beacon moves the campaign forward.

Once a Beacon is cleansed, resting at it revives your equipped Shell, restores Health and Resolve, respawns standard enemies, and updates your respawn point. You also unlock the full Beacon menu, including Level Up, changing your Shell and equipment, Mether’s Pulse, and fast travel back to Marrow Keep.

Clearing the Mawbreak Cavern

At the Beacon, choose “Cleanse Beacon” and step into the portal. This drops you into a dark cave corridor that opens up into the Mawbreak Cavern.

Move into the cavern with the red soil and shallow water. A flying bat-like enemy attacks here, so deal with it before pushing forward.

From the cliffside, switch to a ranged weapon and pick off the distant flying and ground enemies. Thinning them out from range keeps you from getting swarmed as you advance.

Cross the wooden suspension bridge over the chasm to reach the next stretch of the cavern.

You will pass a glowing white statue. Striking it spawns a large spectral beast that is aggressive but does not need to be killed. Run through the red tunnels to evade it, and clear any flying enemy that gets in your way.

Note: The spectral beast is a bypass encounter. If you would rather not fight it, keep moving and it can be left behind.

Grab the Blackblood Stone Tarstone

Near the end of the cavern sits a stone sarcophagus. Open it to obtain the Blackblood Stone, a Level 1 Tarstone. It triggers a “New Tarstone Acquired” prompt and can be checked in your inventory under Tarstones.

Detail	Value
Item	Blackblood Stone (Level 1)
XP to next level	0 / 10000
Faction	Faction Incompatible
Effect	Projectiles explode mid-air and deal splash damage
Splash damage	Exploding projectiles deal 2.5 splash damage

Cleanse the corruption and claim the Ovum

Past the sarcophagus, the path is blocked by red fleshy barriers. Destroy them, and shoot the wall-mounted pods to open the way to the corrupted structure.

Interact with the structure and select “Cleanse Corruption.” This triggers a “New Ovum Found” prompt asking whether you want to collect the Ovum and return to the Beacon.

Confirm to collect the Ovum. Picking it up automatically teleports you back to the surface, and the Beacon now reads as cleansed.

You know it worked when the “Beacon Cleansed” message appears, the Pulsing Caves Beacon shows its full menu, and the “Rest at Beacon” option is available. From there you can rest to lock in the new respawn point.

With the Ovum banked and the Beacon cleansed, the Pulsing Caves become a reliable checkpoint inside Sanguine Caverns. Keep the Blackblood Stone in mind if you run a projectile-heavy build, since its mid-air explosions add splash damage to your ranged attacks.