General Kai, also called Chief of the Yaungol, and the "Fist of the Uuruk" is a yaungol warlord who serves as the General of the Uuruk, the rebel faction from the moon of Heraklon in Araboth. Kai was one of they key members who helped found the rebellion, and was one of the first to side with Lady Sylvanas Windrunner in the war, and was unquestioningly loyal to the Dark Lady and the cause. He led his troops to battle and victory on countless occassions against the Alliance of Heraklon. This earned him the title of "Fist of the Uuruk". General Kai is among those credited with initiating the terrible Great Devastation, when the Burning Legion invaded all realms of Mundus, a conflict that caused untold destruction and innumerable deaths.
Late in the War for Heraklon, Kai began to hear whisperings, from beyond the vastness of space, from an unknown entity. The voice told him to seek out an ancient artifact buried underground, one that could help secure victory for the Uuruk. Kai ordered a massive excavation, one that he claimed was "a search for resources". After eventually finding it, he discovered it was an ancient Annanaki energy beacon, but he believed it to be a tool of the Gods.
Within the large dark chamber that housed the artifact, Kai spent days communicating with his "god" which revealed itself as "The Savior Spirit". This Spirit eventually controlled Kai's mind and made him gather his allies and to convince them into servitude of the Spirit, and to use the device as a conduit or power source to open a portal, one that could help Kai achieve victory over the Alliance. After gathering all his comrades and showing them the device and revealing to them his visions, Sylvanas was frankly appalled, and revealed the voice to be that of Kil'jaeden, the Lord of the Burning Legion. Kai remained stubbornly loyal to the promise of power and victory, and threatened all present to join or die. In her frustration with her traitorous general, Sylvanas insulted him, which led Kai to fly into a rage, battling and nearly murdering Sylvanas. However, the wounded Sylvanas escaped. Kai ordered the traitor Uuruk leaders to muster their forces and prepare for the Legion's arrival.
Little did Kai realize, that he had started far more than he'd bargained for. Aside from activating the power source needed to open the great Dark Portal for the Legion, Kai also awakened an ancient power, almost as ancient as the legion. The Highbreed Empire awakened from slumber in deep space by the primordial energy surging through the void.