The Underworld, or the abyss, is a location which appears only in Blood Omen: Legacy of Kain. It was an afterlife of sorts in Nosgoth, a "fiery oblivion" of howling souls dominated by Mortanius, the Guardian of the Pillar of Death. Kain was depicted as a captive transfixed in the Underworld following his death in Ziegsturhl, and his transformation into a vampire was portrayed here.
On a journey from Coorhagen, the young nobleman Kain stopped at a bar in Ziegsturhl to sate his thirst, but was turned away by its proprietor. As he departed to resume his travels, he was set upon by a group of brigands and quickly assassinated, stabbed to death with an Iron Sword.[Blood Omen] He found himself in the Underworld: a "ghostly burning land", one "populated by lost souls that howl within the abyss".[Blood Omen/1]
Kain was "strung up between two posts, transfixed with [the Iron Sword]", and constrained by shackles around either wrist. As he struggled, the Necromancer Mortanius strode forth from the distance behind him, and twisted the sword free from Kain's body. He released Kain from his bonds, and held the Iron Sword out to Kain, hilt first. Kain stared "contemplatively into the yawning fire" of his environs, then grasped the Sword.[Blood Omen/1]
In accepting the blade, he had consented to an unspoken bargain. "Coruscating magic [rippled] across Kain's body, transforming his white armor to black, living skin to dead vampiric flesh". He had become a vampire, transformed by Mortanius to exact his revenge. Mortanius laughed encouragingly as Kain walked away through the fires of the Underworld. Kain then "awoke to the pain of a new existence" in his Mausoleum, and initiated his quest.[Blood Omen/1][Blood Omen/2]
The Underworld was effectively a contemporary portrayal of Hell; it incorporated a crimson sky and a fire and brimstone aesthetic. The area seen consisted of a jagged, gray stone promontory overlooking a pit wreathed in flames, skirted by an arcane circle decorated with magic runes.[Blood Omen/1]
In script directions, the Underworld is described as follows: "populated by lost souls that howl within the abyss. Their shapes twist and writhe in their fiery oblivion. Through this ghostly burning land, the Necromancer Mortanius strides as its master. Kain is strung up between two posts, transfixed with a sword".
Developments in the Legacy of Kain series which followed from Blood Omen: Legacy of Kain raised retroactive questions as to the nature of this Underworld. Legacy of Kain: Soul Reaver introduces an alternate version of Nosgoth's afterlife: the Spectral Realm, a warped mirror plane of the Material Realm inspired by German Expressionism, very different to the Inferno-like Underworld from the preceding game.[Soul Reaver] Legacy of Kain: Soul Reaver and Legacy of Kain: Defiance also feature subterranean areas described as the Underworld, both of which are seen exclusively in the Spectral Realm and are inhabited by the Elder God.[Soul Reaver][Defiance]
Series director Amy Hennig confirmed that "the Underworld is in the spectral realm"; this comment presumably encompasses this Underworld as well as others. Further, in Legacy of Kain: Defiance, it is discovered that Mortanius resurrected Kain using the Heart of Darkness; this is not transmitted in the Underworld resurrection cutscene. That point, and the fact that Kain awakes in his Mausoleum when the scene ends, may suggest that the Underworld in Blood Omen: Legacy of Kain should be considered an abstract or symbolic representation of what Kain's soul experienced while disembodied - not necessarily a truly literal setpiece.[Blood Omen/2][Defiance/10]
The scene in the Underworld is titled "Kain in the abyss". This name probably does not imply association with the physical Abyss in the Lake of the Dead from Legacy of Kain: Soul Reaver, but is perhaps the one referenced within Blood Omen: Legacy of Kain when Vorador muses that "it would be such a pity to lose [Kain] to the Abyss", and in the Legacy of Kain: Soul Reaver backstory where Raziel mentions that "to raise a vampire, one must steal a soul from the abyss to reanimate the corpse".[Soul Reaver][Blood Omen/6]
- The assets used for the Underworld closely resemble those of two other locations seen in the Legacy of Kain series. The distinctive runic circle and clifftop promontory are closely similar to the room in Avernus Cathedral where Mortanius condemns Malek in Blood Omen: Legacy of Kain, and to the Turel's Pit room in Legacy of Kain: Defiance.[Blood Omen/1][Defiance/10] The three areas are united by their connection to Mortanius, and it is entirely possible, though unconfirmed, that they are all one and the same, reinterpreted for the purposes of each cutscene.
- Legacy of Kain: Defiance reveals that Mortanius can access the Spectral Realm; Raziel can approach him in either the Spectral or Material planes and still interact with him as normal.[Defiance/10] Mortanius's mastery over the Blood Omen: Legacy of Kain Underworld may be taken as prior evidence that this is indeed the case.
- Legacy of Kain: The Plot at SK: The Complete Guide To Legacy of Kain (archived at Dark Chronicle)
- Blood Omen Scripts at The Lost Worlds (by Ben Lincoln)
- Behind the Classics: Amy Hennig Talks Soul Reaver Secrets at the PlayStation Blog (by Sid Shuman and Amy Hennig)
- Warp's answers from Amy at the Square Enix Forums (by blincoln)
- Mortanius the Necromancer at Dark Chronicle (by Ardeth Silvereni)
- Theme Outlines for Cinematics at SK: The Complete Guide To Legacy of Kain (archived at Dark Chronicle)
- The Abyss at Dark Chronicle (by Ardeth Silvereni)
- Soul Reaver: Background Story at Dark Chronicle (by Ardeth Silvereni)