Sparkmancer Vu served as the Thunder King's most trusted advisor.
Born into the same tribe, the two mogu grew as close as brothers. As children, they played, quarreled, and challenged one another. It is said that this early rivalry was instrumental in developing Lei Shen's thirst for power. Vu, however, fought fiercely to help Lei Shen win the throne of Pandaria.
Not long after Lei Shen gained reknown, the Sparkmancer was captured by enemy assassins and his tongue was cut. Popular opinion suspected the Thunder King himself was ultimately behind this plot, a political move to silence the one mogu who knew his deepest secrets. Their brotherhood was also the source of much conjecture and fiction. The peasant masses enjoyed writing stories, including a famous saga about their feud over a woman.
Despite these rumors, history shows that Sparkmancer Vu never wavered from his commitment to his Emperor; he served his friend and brother loyally to the end of his days.