Ghaul

Dominus Ghaul is a Cabal soldier and the leader of the Red Legion. He is the main antagonist of Destiny 2.

Biography
Ghaul was raised as a child to believe that he and his legion, the Red Legion, are the rightful beneficiaries of The Traveler's powers. He came to believe that The Traveler made a mistake in choosing Humanity and the Red Legion would have developed into much stronger and more powerful Guardians.

At some point, Ghaul attacked and destroyed the Guardians' City in an attempt to prove his legion's worthiness to The Traveler.