Overcharged Fel Core

Source
This item drops from the following Legion Assaults commanders in the Broken Isles:
 * Dread Vizier Gra'tork in Val'sharah
 * Fel Commander Erixtol in Highmountain
 * Xeritas in Azsuna
 * Lord Commander Alexius in Stormheim

As a quest objective
This item is an objective of Fel to the Core.