Crystal of Unstable Darkness

Crystal of Unstable Darkness and its ingredients are one of the rarest, if not the rarest, items in the game. The player that manages to obtain all 4 of its ingredients will be able to synthesise it and obtain a special colored title:

Vanquisher of Darkness,

Kzarka Summon Scroll and also choose between one of these three:

• 
  Splendid Alchemy Stone of Protection
• 
  Splendid Alchemy Stone of Destruction
• 
  Splendid Alchemy Stone of Life

How to craft the Crystal of Unstable Darkness

In order to be able to craft

Crystal of Unstable Darkness you'll have to combine:

• 
  Crystal of Depravity
• 
  Crystal of Corruption
• 
  Crystal of Wickedness
• 
  Crystal of Repugnance

and then synthesise them using simple alchemy. Once the item is crafted you can accept the quest

[Alchemy] Incomplete Evil God and exchange the crystal for

Kzarka Summon Scroll. After that you'll be given a guaranteed

Kzarka's Sealed Weapon Box and also be able to choose between the before mentioned Splendid Alchemy Stones.

How to obtain the ingredients

Actually obtaining the ingredients is where the real challenge lies. Many myths surround the aquisition of these ingredients, but this will give you a final answer whether they are even obtainable and if they are, how to obtain them.

Item 1: Crystal of Corruption

Crystal of Corruption is the first ingredient of the Crystal of Unstable Darkness, obtained through alchemy.

With each alchemy craft you do you have a chance to roll an event group. The odds of hitting that group range from 0.3% at 0 mastery up to 5.7% at 2000. When successfully rolling that event you then have to hit another rare byproduct group. The chance for rolling that group varies based on mastery again and is between 2% at 0 mastery and 4% at 2000 mastery. On each successful roll of that group you then have a ~0.0001% chance of actually obtaining

Crystal of Corruption.

Item 2: Crystal of Wickedness

The second ingredient,

Crystal of Wickedness can be obtained by grinding down any type of alchemy stone or spirit stone.

You can find the recipes and yields for every stone in the "Product of Processing Recipe" tab of

Crystal of Wickedness. The chances of obtaining the second crystal are very low as well with a droprate of 0.0001% per successful grinding process.

Item 3: Crystal of Repugnance

Instead of needing to destroy alchemy stones like for the last item,

Crystal of Repugnance can be obtained crafting new alchemy stones or spirit stones. In order to create new alchemy stones you need to combine:

• 10x
  
  Shining Powder
• 3x
  
  Sinner's Blood
• 5x
  
  Powder of Time
• 10x
  
  Pure Powder Reagent
• 10x
  
  Clear Liquid Reagent

This will then either give you:

• 1x
  
  Imperfect Alchemy Stone of Destruction
• 1x
  
  Imperfect Alchemy Stone of Protection
• 1x
  
  Imperfect Alchemy Stone of Life
• 1x
  
  Broken Alchemy Stone Shard
• or with a 0.0001% chance
  
  Crystal of Repugnance

Note that the 3 Imperfect Alchemy Stones could then be broken down again for a chance to obtain

Crystal of Wickedness.

You could also try to obtain

Crystal of Repugnance by crafting Spirit Stones, the recipe for all them can be found on the database page of the Crystal of Repugnance under "Product of Recipe".

Item 4: Crystal of Depravity

Now onto the final ingredient,

Crystal of Depravity which is by far the hardest to obtain.

The reason for that is the fact that it's only obtainable via turning in Imperial Alchemy Boxes. Each day you have a limit that dictates how many of those you can deliver. The formula for that limit is: contribution points / 2. Combine that with a drop rate of 0.0001% per box and you'll see it takes a serious amount of time to obtain the final ingredient.

To make things much worse though it can only be obtained by turning in the old Imperial Alchemy Boxes. Some of you may have never even heard about them as the rework of those boxes happend back in 2019. Instead of boxes being grouped by skill level like Guru, Master etc. every meal/elixir had its own box like this one

Professional's Sturdy Alchemy Box. Unless you for some reason have a insane stockpile of those old boxes left your chances of every dropping

Crystal of Depravity are basically 0.

Item 5: Crystal of Deterioration???

Wait but what about

Crystal of Deterioration?

While it looks and sounds like this item should be part of the ingredient list it's actually not. There is no way to obtain it and even if you could - it wouldn't be part of the actual recipe as you can't interchange it with any of the other ingredients. Maybe this one has just been forgotten about or is a placeholder for future things.

The Numbers

Now that we've seen all of those stats let's put them together and see how long it would take to obtain all 4 ingredients:

Crystal of Corruption: 5.7% * 4% * 0.0001% = 0.000000228% @2,000 mastery. Assuming a 1.2 second alchemy time including lag between craft that turns out to ~439,000,000 crafts and 146,000 hours of alchemy or roughly 25 years of doing alchemy 16 hours a day.

Crystal of Wickedness: 0.0001% per grind. With 9s grind time and 100% success rate that turns out to 2,500 hours or 156 days of grinding 16 hours a day.

Crystal of Repugnance: Similar to the last item, 0.0001% per craft. With 1.2s craft time that turns out to "just" 333 hours of solely crafting alchemy stones.

Crystal of Depravity: Since the boxes to turn in are no longer obtainable it doesn't really make sense to worry about this one, but in case Pearl Abyss decides to add them to the current Imperial Alchemy Boxes and leave chances the same: 0.0001% per box @500 contribution points requires you to turn in 1,000,000 boxes over 4,000 days or just shy of 11 years of imperial turn ins.

Conclusion

To wrap things up, getting all 4 required pieces for the Crystal of Unstable Darkness is a extremely hard task. And even that is probably an understatement. Let's hope the developers add

Crystal of Depravity to the current Imperial Alchemy Boxes so that atleast it becomes theoretically possible to obtain all 4 pieces.

Best of luck to all of you who are trying to obtain this item or atleast one of the ingredients. I hope this guide helped to set some expectations and maybe get Pearl Abyss to look into adding new ways of obtaining the Crystal of Depravity^^