The Compound system, accessible by pressing SHIFT + P, is a new enhancement system designed to help boost your character’s base stats by adding unused accessories and fusing them with Runes. Compound allows for a total of 6 different items to be registered. However, choose wisely; accessories that are used in the Compound system cannot be retrieved.
To start, if you hover your cursor over a Legendary-tier accessory, you'll find a new system: Power Potential. Each accessory has a different amount of Power Potential based on its tier:
The higher the Power Potential, the higher stats you'll receive after adding them to the Compound system.
Once accessories have been placed in the Compound system, all that's left is to acquire Etching Stones to engrave stat bonuses onto Runes.
Acquired from the Midnight Skypetal Plains, Etching Stones are used to activate Runes in the Compound window. Press the + button to open a list of available Etching Stones to add in. You will get different amounts of stats depending on the tier of the Etching Stone and different type of stats depending on which Rune it is, which is based on chance. Currently, the following Runes are considered the strongest for fighting creatures of the wild:
To the right is a list of the different types of Runes and the stats you can receive from each. Below is a list of different Etching Stone tiers:
Hongmoon Etching Stone: Engraves Refined or Superior stat boosts.
Burnished Hongmoon Etching Stone: Engraves Refined, Superior, or Heroic stat boosts.
Searing Hongmoon Etching Stone: Engraves Superior, Heroic, or Legendary
For a first-timer delving into the system, figuring out the functionality of Compound can be tricky. Here's a short guide to how it works and which button does what:
Choosing your Runes
Step 1: Selecting the Rune
In the screenshot to the left, I wanted to switch my Creation Rune. By hovering over it, a tooltip shows up to detail its stats. Left-clicking the Rune opens a new window.
Step 2: Selecting which Etching Stone
In the new window, there will be a list of the different Etching Stones that can be used to engrave the Rune onto the Compound system. In my case, we have the Burnished Hongmoon Etching Stone and the Hongmoon Etching Stone. At the bottom of the GIF, you can also see which ingredients and gold that the Etching process will consume.
Step 3: Selecting which Rune to keep
In the window Old Attributes, you can see my current stats that I got from the Creation Rune. When I press Apply Etching, the Compound system will show which new Rune you got, which is based on chance. Now it's up to you to choose!
In my case, I first received the Compulsion Rune which grants Evasion and Debuff Defense. I preferred my old Creation Rune and therefore pressed Keep, which discards the new Rune. Next I received the Aggression Rune which granted Mystic and Boss Defense. This was more to my liking, which is why I pressed Change to discard my Creation Rune and kept the Aggression.