Bronjahm was the foreman of the soul grinder engines. After learning from Kel'Thuzad himself the value of souls and how to grind them down to fuel the engines of the Scourge. He patrolled the Forge to ensure that no interruptions befell the engines' operation.
The Devourer of Souls was the chief operator of the soul grinders, dedicated to preventing souls from escaping the dark machines. It would consume stray spirits and break them down.