How to Get Pure Energy Residue in The First Descendant

You are probably here looking to craft the Ultimate Bunny Spiral Catalyst in The First Descendant. It needs Pure Energy Residues, but these rare materials are hard to find, and you need many of them. Even if you know where to find them, you’ll still need a great farming spot to make your farm much more efficient. Here’s how to get Pure Energy Residues in The First Descendant.

Where to Get Pure Energy Residue in The First Descendant

Pure Energy Residue drops from Encrypted Vaults in the Fortress region. You’ll need to search for these Encrypted Vaults while having Codes (Breakers and Analyzers) to open them. Roam all the battlefields in the Fortress region and use your Ecive Scan to look for Encrypted Vaults. You can look for those faded holographic icons on the floor so you know that Encrypted Vaults are spawning around the area.

While roaming the Fortress, you can farm Munitions and Resource Boxes to farm Hellions and Reversed Charging Coils for other research. You can also run missions to get Polyatomic Ion Particles, which are used for crafting Energy Activators.

It is worth noting that Pure Energy Residue also drops from monsters in almost all the missions in the Fortress. However, the drop rate is so low that it isn’t a viable farming strategy. You can get one or two pieces after finishing five missions, and that is already a bit lucky.

Best Pure Energy Residue Farming Location

Finding Encrypted Vaults is tedious and difficult. You can read up on our Encrypted Vault guide to learn the best tricks for finding them.

After learning the best way to find Encrypted Vaults using the Ecive Scan, you should go to the Frozen Valley battlefield in the Fortress. In the image above, multiple Encrypted Vault spawns are close to each other. They’ll rarely spawn together, but you have a high chance of finding one whenever you roam the area with the red circle.

You can go back and forth from each waypoint. Once you have opened an Encrypted Vault, you can switch difficulty using the map menu before fast traveling to a waypoint. You’ll reset the instance and look for another Encrypted Vault until you have enough Pure Energy Residues. So far, this is the best Pure Energy Residue farm location since the battlefield is narrow enough to catch everything with an Ecive Scan while having multiple Encrypted Vault spawns.

What Are Pure Energy Residues Used For?

Pure Energy Residues are used for the following research:

Ultimate Bunny is one of the strongest Descendants, and if you are looking to min-max her stats or build, you’ll need her Ultimate version as much as possible. You need 89 Pure Energy Residues to craft Ultimate Bunny’s Spiral Catalyst. It would take several Codes to open enough Encrypted Vaults to reach this number.