The Codex of Power is a new and important feature that helps you keep track of all legendary aspects in Diablo 4. You can check from here the aspects you have unlocked, their unique effects, and class requirements. You can also pin aspects to your map to track them down to complete your Codex collection.
You can access your Codex of Power by either heading into the Collections menu or using its keyboard shortcut (Y) on PC.
In Diablo 4, legendary aspects are powerful upgrades that are crucial for the endgame by vastly improving one of your skills or your build overall.
If you are looking to run dungeons in the World Tier 4 difficulty settings, you are going to need to deck out your character with the best Codex of Power aspects possible in Diablo 4.
How to unlock Codex of Power Aspects in Diablo 4
There are two types of legendary aspects in Diablo 4. For the most part of the game, you are going to be unlocking aspects by clearing all dungeons across all five regions on the map.
The Codex of Power will activate when you complete your first dungeon. Its legendary aspects will automatically be added to your Codex alongside a notification on your screen.
For example, if you manage to clear out the Sirocco Caverns Dungeon, you are guaranteed to find the Aspect of Echoing Fury inside, which, coincidentally, is one of the best Barbarian Aspects you can find in Diablo 4.
Something important to note here is that the buffs obtained from your Codex aspects are not always going to have the maximum possible value.
Here comes the second type of aspect in D4, the non-Codex or extracted legendary aspects. These are not unlocked from dungeons and are not found in the Codex of Power.
You get them by extracting them from legendary gear. In other words, you have to farm high-level nightmare dungeons to loot an item with a non-Codex aspect.
Then find an Occultist to extract the aspect into your inventory. Imprint it on a gear to get a higher overall bonus yield compared to your Codex of Power aspects.
The only problem is that Aspects not added to the Codex of Power can only be used once.
How to equip a Legendary Aspect in Diablo 4
To equip a Legendary Aspect in Diablo 4, you will have to imprint it on a suitable gear item first. This can be done through an Occultist. However, it will require a little bit of Gold and Veiled Crystals.
Both Codex, and non-Codex Aspects can be imprinted on Rare/Legendary gear items at the Occultists, but the non-Codex items can only be imprinted once.
Simply go to the Occultist at any place of your choosing and go to the vendor’s menu. Here, you’ll find a slot where you can place your item. Below this section, you can find Aspects in your Codex of Power. You can also select non-Codex Aspects from your inventory.
Once you have selected your desired Aspect and a suitable gear item, you can select the Imprint option to attach the Aspect and make the item receive its bonus.
After that, it’s only a matter of equipping the gear item to reap the Aspect’s perks. It is important to make sure that you select the correct gear items when imprinting Aspects onto them, as each Aspect has a varying amount of stats depending on the ger item it’s being imprinted upon.
For example, if an Aspect works perfectly with a two-handed weapon, then that means it might not be as effective with a one-handed weapon. It’s all about selecting the best item for a particular Aspect.