The Harrowing Adventures of Winston, Warbastard, and "Friends"
Black Diamond is a ruthless, efficient killer, known for his mastery of the rooftops of the cities and his quick, clean kills using a variety of techniques. He is a master poison maker and deadly with a blade.
He was ordered by the Drow Empire to assassinate important senators of Oceanstar who were going to vote to sever connections with the other human city-states. As a result, the Senate would see these killings as evidence that the Drow wish them to open their ports again to the other city-states and thus open to further attacks. In reality however, the Drow wished for all the Human city-states to seclude themselves, as they knew that a united Human front would make conquering the land much harder. The In-Glorious Basterds caught Black Diamond and convinced him that it was in his best interest to not take jobs for the Drow, who would only kill him when he outlived his usefulness anyway. With Black Diamond’s aid, the In-Glorious Basterds revealed the sinister plot to the Ocenstar Senate and convinced the senators of Oceanstar to strengthen relations with their neighbors and fortify the human position as a whole.