Sanctum: Stonebound Sword is a hidden sanctum in Russet Highlands that only appears once you activate it with a Pawney. Here's how to get a Pawney, how to make the sanctum appear, and what's waiting inside.
Where to Find Sanctum: Stonebound Sword
Once activated, Sanctum: Stonebound Sword appears in the northern part of Russet Highlands.

How to Get Pawney
You need a Pawney to make the sanctum appear. You get one by completing the Journey quest Warrior under The Legend of Helmuts and Helgons. Along the questline, you can evolve your Helmut into Pawney.
Warrior is a Russet Highlands quest, and its quest target is to find clues in Russet Highlands to restore the painting. Its recommended level is 48.

To start Warrior, talk to Sorora in the western part of Russet Highlands, near the Rainbow Woods Bloom Branch. The map clue says the painter Sorora is at the Helmut Habitat, troubled by a blurry painting.

How to Unlock Sanctum: Stonebound Sword
Sanctum: Stonebound Sword is a hidden sanctum, and it doesn't appear until you activate it. To activate it:
- Twine with a Pawney
Twine with a Pawney. Any Pawney form works.
- Interact with the empty platform
Interact with the empty platform in front of the spot where the sanctum will appear.
- Select Return the treasure.
The game tells you the platform is empty and the treasure is nowhere to be found. Select Return the treasure.
- The sanctum appears
Sanctum: Stonebound Sword then appears.

Sanctum: Stonebound Sword Objective
It's a solo sanctum for 1 challenger, and it has only 1 chest.

The sanctum's objective is to reach its heart and restore the Vein.

How to Solve the Stonebound Sword Puzzle
There are no puzzles to solve inside the sanctum. Simply claim the chest, then head to the heart of the sanctum to restore the Vein.

Repair the Vein and Claim Your Reward
The first-clear reward is Lumin Amber x1 and Character EXP x500.

How to Find, Unlock, and Clear a Sanctum · Lumin Amber: Location Map, Uses & Branch Rewards · All Guides