Tar Goroth

Tar Goroth is the Balrog who was awakened by the Orc Sorcerer Zog. The orc wanted to use him to defeat Sauron and take power over Mordor.

Lore
During the First Age, Tar Goroth was a general under Sauron in Morgoth's army when the first Dark Lord battled the Host of Valinor and the Free People. At the end of the War of Wrath, the Balrog was defeated by Carnán

Throughout the second age he remained trapped.

During the Third Age, the Darkness returned and Tar Goroth  was awakened. He was brought back from death by the orc necromancer Zog. Talion attempted to subdue him but Tar Goroth escaped. He would later be defeated by Talion with the help of Carnán, and frozen in a lake