Grand Admiral Grant
Grant was one of the twelve original Imperial Grand Admirals appointed by Emperor Palpatine two years before the Battle of Yavin. A former Tapani noble, Grant saw himself as superior to those who were not members of the nobility, and held a particular dislike for droids and other species. His Humanocentric beliefs stood firm after he joined the ranks of the Galactic Empire, and he proved himself to be an expert military strategist. Due to his military talents, he was appointed as one of the twelve Grand Admirals created by Palpatine in 2 BBY, though he was one of the least popular Grand Admirals, and did not attempt to curry favor with the Imperial moffs.
After leading several successful campaigns during the Galactic Civil War, Grant was left virtually alone after the Emperor's death over Endor, as he had not built up a sturdy following as the other Grand Admirals had. Grant bided his time, laying low in the Pentastar Alignment while his fellow Grand Admirals were hunted down by the New Republic. Eventually, with the other Grand Admirals all dead, Grant defected to the New Republic, providing key Imperial secrets in exchange for immunity from charges of war-crimes.
However, Grant used this freedom to secretly construct a large fleet, including the Super Star Destroyer Bloodlust. In a sudden move, Grant managed to rejoin the Imperial Remnant and strike out at the New Republic. However, the union was short lived, with Grant striking out on his own, acting independently of the Remnant. (ref) He also 'recruited' Shira Brie to his cause. Whether this was because he wanted or needed her talents, or because he wanted to have his own pet Sith (acting as Vader to his Palpatine) is unknown.
Grant is a military genius (like all Grand Admirals) and is very good at piecing together complicated plans and machinations in order to topple his foes with minimum effort.