Grurn

Grurn is a undead lich who resides in the tomb under Fort Firemoth.

Sellus Gravius will tell you that Grurn "literally marched out of the ocean and overran the garrison there". The lich has a unique shield, the Ward of Akavir, which the Imperial Legion wants to take back.

Quest
Siege at Firemoth: He carries the Ward of Akavir which you need to recover and is the final boss in the quest.