Salt and Sacrifice has a lot of NPCs that can sell you different items. All these NPCs can be spawned in your camp in different locations. When you start the game, you will first have almost nobody at your camp, but by completing certain missions and joining factions, you will unlock NPCs and they will come into your camp.
This guide will show you how to unlock the Material Merchant in Salt and Sacrifice.
Salt and Sacrifice: How to Unlock Material Merchant (Where to Use Drowned Key)
To begin your journey, you must first have the Drowned Key obtained from the Hallowed Hill Region.
Enter Mossgrave and into this cave, you will need to continue going left. Inside this cave, there will be a lot of obstacle courses and wind blowers that will take you up to incoming areas. Be aware of traps.

A good thing about getting to your desired location is that there are no other paths, you will need to follow the given path and go higher and higher.
You will find another entrance to a different area once you stumble upon a set of wooden stairs.

Enter the area and you will go inside the Revenant’s Keep.
This area also has only 1 way and you simply need to follow the path and complete the obstacle courses.
At the end of this area, you will find another gate from where you need to previously fall down on some wooden platforms and you will find the entrance on the left side.

Once you enter the next area, you will see two wooden platforms that you can drop onto and the path will split by letting you go left or right. Continue going right in order to make sure you are on the correct path.

As you continue going right, the path will split again into two different ways, up and down. Don’t take the stairs down, jump up and continue going right when reached the stone platform.

In this area you need to be careful as there are a ton of traps.
Once you reach the end of the road, you will see a doorway that will take you outside. The path in this area will be simple, you need to follow a set of hooks and wind blowers in order to get to your next destination.
When you reach the area presented on the image below, a fallen knight will be found, simply wait for him to get up and he will unblock the gate behind him.

Enter the area on the right end of the room you will find the Drowned Key.

With the Drowned Key obtained, return to your camp and go to the very bottom left side of the camp where you can now unlock the door.
NOTE: You need to have found at least 1 of the 3 evil factions for this area to be opened.


ALSO READ: Salt and Sacrifice: How to Join the Oathbound Watchers