Connor the Darkcaster, formerly of the Undead Scourge, is a Death Knight and leader of the Shadow Horde. He is unafilliated with either the Alliance of the Horde.
Connor was chosen by the New Lich King, moments before entering his dormant state, to act as a new captain for the Undead Scourge, charged with overseeing the defence of the eastern section of Northrend. After the Lich King was defeated, and a new Lich King crowned, Connor left on his own and ventured to the Broken Isles. There he managed to seize control of many of the warring Orcish Revenants and began to formation of the Shadow Horde. Upon returning to mainland Lordaeron, he made contact with a group of Forest Trolls and enlisted (read as enslaved) them to join his Shadow Horde.