Mortal Shell 2: How to Get the Lost Clotstone Tarstone

The Lost Clotstone is an Ability Tarstone in Mortal Shell 2 that turns your primary weapon into a projectile. Once equipped, it lets the Harbinger spin and hurl the weapon for heavy splash and single-target damage, and it only drops from one fight in the game.

Quick answer: Defeat The Lost Child, the final boss of the Sanguine Caverns Gate in the Child’s Feeding Grounds, and the Lost Clotstone drops as a guaranteed reward.

What the Lost Clotstone does

The Lost Clotstone is infused into your Primary Weapon and consumes Resolve to release a spinning weapon throw. At its base state the throw costs 60 Resolve, and each upgrade level adds damage or lowers that cost. The full effect list is below.

Level	Effect
Base	Consume 60 Resolve to spin in place and release your weapon with brutal force
1	The thrown weapon deals 200 splash damage on impact
2	The thrown weapon deals 300% damage to the struck target
3	Resolve cost reduced to 40

It only works with two weapons. You can equip it to the Obsidian Hammer or the Veteran’s Battle Axe, and it will not attach to anything else. If you try to slot it onto an unsupported weapon, the menu marks it as incompatible.

Tarstones inventory menu showing an Ability stone with its infusion upgrade options listed — The Tarstones inventory screen, where Ability stones and their level upgrades are listed. Image credit: Cold Symmetry / via @SharkR

Where to find the Lost Clotstone

The route runs through the Sanguine Caverns and out to the Sanguine Shoreline, ending at a boss arena on the coast. Reaching the fight is the only requirement, and the drop is fixed once the boss dies.

Enter the Sanguine Caverns and follow the path deeper into the area. Push forward until the cavern opens toward the shoreline section.

The Sanguine Caverns area title appears as the armored character moves toward enemies in the cavern — The Sanguine Caverns area, the starting stretch of the route to the boss. Image credit: Cold Symmetry / via @SharkR

Continue to the Sanguine Shoreline and reach the final Beacon there. This checkpoint sits in a rocky, swampy stretch just before the cave entrance to the fight.

Player character with a long polearm approaches a black shrine checkpoint in a rocky swamp — The Beacon checkpoint near the Sanguine Shoreline, the last stop before the boss cave. Image credit: Cold Symmetry / via @SharkR

Head into the cave and speak with Rok, the bird-like NPC. He explains the boss ahead, a giant child banished to the lake and worshipped by disciples as the light.

Player advances through a torchlit cavern toward a glowing blue figure, with HUD elements visible — Approaching the glowing figure inside the cave, where Rok gives context on the coming fight. Image credit: Cold Symmetry / via @SharkR

Enter the arena and defeat The Lost Child. This is the final boss of the Sanguine Caverns Gate, and beating it releases the Lost Clotstone.

The player fights The Lost Child boss in a coastal arena to claim the Tarstone drop — The Lost Child boss fight on the coast, the only source of the Lost Clotstone. Image credit: Cold Symmetry / via @SharkR

Confirm you received the Tarstone

After the kill, the Lost Clotstone lands as a drop from the boss. Open the Tarstones menu to confirm it, where it appears under the Ability type at Level 1 with its splash-damage effect listed. Slot it onto the Obsidian Hammer or Veteran’s Battle Axe to use the throw.

Tarstones menu shows Lost Clotstone at Level 1 with its splash-damage ability description — The Lost Clotstone Level 1 entry in the Tarstones menu after the boss drop. Image credit: Cold Symmetry / via @SharkR

How to upgrade the Lost Clotstone

Upgrading Tarstones requires the Etching Needle, a quest item that expands the Tarforge options in Marrow Keep. You loot it from a bone chest just before the Magdalena, the Lady of the Woods fight. When you spot Ruk past the bridge, drop through the opening and turn right before the tunnel to find the small alcove holding the chest.

Once you hand the Etching Needle to Franz, keep the Lost Clotstone equipped and kill enemies to fill its experience bar. When the bar is full, return to Franz in Marrow Keep and pay Coin to raise it to the next level. Repeat this for each higher effect, up to the reduced 40 Resolve cost at the top tier.