Artifact quest for Cowl of Power
Complete the following:
Defeat 30 Lost at Spire Rock Fort
To unlock Empty Socket
Defeat Salty Sait
To unlock Enchanted Ward
Defeat 30 Lost at Stone Skull Fort
To unlock Health
And
Upgrade at the Gypsum Kiln:
725: Recipe: Cowl of Power Upgrade At the Gypsum Kiln
700: Recipe: Cowl of Power Upgrade At the Gypsum Kiln
To see which perks can be applied, check out the "Perk Bucket" Tab in the Cowl of Power article.