The Hoardseekers are items found in certain dungeons in Darksiders. They reveal the location of all chests on the map of the area. If a player acquires Fury's Embrace later in the game, the Hoardseekers become obsolete. Not to be confused with the Hoardseeker Talisman from Darksiders II.
This is located on the upper levels of the southern courtyard, off the main Cathedral atrium, near the start of the level. You'll need to explode a bomb growth attached to red crystals either by throwing an environment object at it, or by jumping near it and using the Earthcaller horn. Alternatively you can return later when you have the Glaive. Once detonated it will destroy the red crystals, allowing you to jump across and find the Hoardseeker chest.
Towards the end of the level you will need to get past a Beholder Key door that leads into a railway tunnel where Griever will crush railcars using her tentacles. Beyond that tunnel is a large room with water on the floor, which you must clear of enemies. Once clear, the right-hand exit to the room leads to a small set of caves containing a souls chest and the Hoardseeker chest.
The Iron CanopyEdit
Once you obtain the Abyssal Chain, return to the large room with two elevators and a draggble crate with a bomb growth on it. On the lower level head out the door into the alleyway outside. Look up for a red grapple point inside a window, which you can reach by double-jumping from the top of the fire escape. In here is the Hoardseeker chest.
The Black ThroneEdit
On your way to the Second Guardian in the northern section of the map, on the 6th floor. After you have gotten up to the top of the floating platforms by balancing demonic stone blocks on them, destroy a wall of blue crystals to find the chest. Note that you can find the Fury's Embrace weapon enhancement much earlier in this level, almost immediately after you first obtain the Voidwalker, which renders the final Hoardseeker redundant.