Essence of power is a special craft item that is used for corruption and regret essences. You can convert unused uni tokens at the anvil on top of BB. Higher the uni token, more essences you receive.

 

Each essence of corruption will have one of these outcomes:

Destroys the item

Add additional stats

Turn the unique into a different unique of the same level

   

The essence of corruption and greater essence of corruption has two additional outcomes:

Upgrade to a uni of the next level

Grant offense or defense score

 
Once an item is corrupted, unless it rolled as a new uni, it will not be able to be corrupted again.