Dreadful Essence

Dreadful Essence is an artifact item.

Source
Dreadful Essence can be obtained as a drop from the level 50 world boss Dreadtooth in Section X on Belsavis.

Uses
Dreadful Essence is used to increase the stacks of Dreadful Resurgence on Dreadtooth. The number of stacks determines the difficulty of the encounter. It can only be used by Biochems with a skill of at least 400.