The Shadewind Order started out as a group of night elf sentinels, occupying an old Highborne spire; renamed to the Shadewind Spire after themselves.
At some point, the human Renault Blakemore managed to involve himself in the Shadewind Order, rising up to take reins as its commander. With this came a dark, corrupting influence, though it is unknown whether Renault's appointment as head of the order came as a result of this influence or if he corrupted the order after he was appointed.
Either way, Renault took to using the Shadewind Order as a way to recruit hopefuls from across the Alliance, presenting it as an ambitious (if unorthodox) adventuring guild with a focus on slaying wild monsters around Northern Kalimdor. Once new recruits had proven themselves to the order and their loyalty to its cause seemed set, the inner circles of the order would begin to reveal themselves: the order was a recruiting front for the Twilight's Hammer cult.
Renault Blakemore himself, and several of those closest to him, met their end when The Adventuring Party raided the tower on their quest to stop the Twilight's Hammer's operations in Stonetalon.