This quest is found in Aelbeageu, with Anar the guard Aelbeageu City, in the place where the blue dot is shown on the map below:
The mission: Kill 7 Discus Wizards Sealakel. (Discus Sealakel Wizard are found on the north bridge, look in the pink area of the map)
Anar Location
Discus Sealakel Wizard Location