The Priestess was a character originally planned for inclusion Legacy of Kain: Soul Reaver. One of the few non-vampire bosses she and her territory the Undercity were ultimately removed from the finished product and were not present in the retail version of Soul Reaver.
It is generally believed that after defeating Kain in the the Chronoplast and gaining from him the Shift At Will ability, that Raziel would have turned his attention to the Priestess and, passing through the City, would have entered the Undercity and Temple, the lair of the Priestess. Daniel Cabuco confirmed that the entrance to the lair was to be entered through the second water pipe leading downwards in the main Water Tower courtyard area of the City. There he would have fought many Vampire worshippers until facing the Priestess herself who would have summoned 'monsters' to fight Raziel. Upon defeating her he would have gained the Possess ability and freed the Citadel from her influence.
Alpha versions of Legacy of Kain: Soul Reaver revealed publicly by the Lost Worlds and Legacy of Kain Wiki in 2020 were found to still contain the Priestess and her Undercity level. As previously suspected the area was accessed from a water pipe in the human citadel which led down to an expansive settlement beneath populated by Worshippers and occasionally vampires, although progress through the level could be hindered due several water-level puzzles functioning incorrectly. The Priestess herself was present in the area with her boss area accessed from one of the high towers at the top of the Undercity. This revealed the Priestess to be dressed quite differently from the costumed envisaged based on the comics and concept art - with only a pair of straps covering her breasts and numerous clan- related tattoos across her body. Unlike the other bosses in the alpha, the priestess boss fight itself was still largely functional although parts were not properly positioned. In the area as it appears in the alpha the Priestess is positioned on the ground and summons vampires from nearby darkened doorways , but it appears she was intended to be placed on the high ledges surrounding the area instead.
It was previously believed that the depiction of the woman to be the Priestess in the Temple area of Soul Reaver, however, this would appear to be unlikely due to the area being decorated with Sarafan imagery and artist Daniel Cabuco confirmed that the depiction was just an ordinary woman.
Another believed depiction is the Legacy of Kain: Soul Reaver title screen which features a number of stylised statues said to represent the lieutenants. The Priestess was initially said to be among them, but Daniel Cabuco later clarified that the statue represented Malek.
Ultimately the Priestess was depicted in concept art and her likeness based on this image was featured in the Legacy of Kain: Soul Reaver comic. The Priestess that appeared in the alpha bore many of the traits of the concept art but wore a much skimpier outfit and more tattoos, a higher headdress and a colorful dress.
Though she does not appear in Soul Reaver, there are images of her in concept art and the Legacy of Kain: Soul Reaver comic.
The legacy of the Priestess has continued throughout the series: Soul Reaver 2 originally featured a Vampire worshipping cult, that was removed (this led to the Feral humans appearing in Legacy of Kain: Defiance). Defiance also originally had Umah fulfilling a similar role to that of the Priestess (before she became a vampire). This was also removed.
Given the likelihood that Kain must eventually return to the era of his empire, the possibility remains that the Priestess will return in her original form.