Blackhand the Destroyer, also known as the Warlord of the Fel Horde, is a massive and powerful ork warrior who was hand-chosen by the warlock Gul'dan to lead the orkish Fel Horde as the Warlord - commander of the entire orkish military.
Blackhand is a devout follower of Gul'dan. It is believed that Gul'dan found the ork who would become Blackhand, as an infant, and cared for the creature. Since orkish psykers such as Gul'dan are born, not trained, the ork could never become like his adopted father, and instead was trained in the pits to become a warrior. Gul'dan taught Blackhand things that the WAAAGH academy would not, however. Things that would come in extremely handy in the future, when he seized control of the orkish people during the period of time known as the Great Devastation.
Gul'dan was like a father to Blackhand, and when the orkish warlock rallied the furious inhabitants of Orsinium together under one flag - the flag of the Burning Legion, Blackhand was eager to rise up the food chain along with his adoptive father. This opportunity presented itself when the former Warlord, Krolag, was killed for betrayal of the warlock Gul'dan. After this, Blackhand offered to take the role of Warlord of the Fel Horde, and bring glory to the orks through bloody conquest and faithfulness to the demonic Burning Legion. Gul'dan accepted, and since then, Blackhand has battled on the front lines with his orkish armies, as they carve bloody paths to victory through the Velous nations of planet Earth.
All across Velous, Blackhand's name is feared and dreaded, for he has earned the title of The Destroyer, because to Blackhand, there is no enemy he cannot destroy, no challenge he cannot surmount. No task that will shake his loyalty, and his unfailing ability to kill everything that stands between him and victory, in the name of Gul'dan and the Burning Legion.