See Zul'Farrak NPCs.
His name might also be a reference to Commander Bly, a Clone Commander in the "Star Wars" universe, who along with the whole Clone army betrayed the Jedi Knights.
He and his party of comrades will begin to hearthstone out after some time. if you speak to Sgt. Bly during this time, he will engage and his party will leave him to his inevitable fate. However, you must do it near the time that his party will hearth, otherwise, you will have to fight them as well. Sometimes, if more than two at a time talk to him, his party will turn hostile, but Bly will remain friendly and help kill his friends. However, when they are dead, he will get aggressive again.