Thralls were undead warriors, re-animated and tasked with eternally protecting the sacred places of the Ancient vampires against intrusion, rising from underground to confront Raziel as he approached[Soul Reaver 2 manual][Soul Reaver 2 strategy guide (Prima)]
Thralls could be divided into three variant sub classes:
- Swordsmen thralls were the regular close range class armed with Short Swords.
- Sorcerer thralls were long range specialists who fired projectiles from distance.
- Greater thralls were the mid range class armed with Scimitars. This class was more powerful and displayed seniority over the other classes. Often they could be found using Emblem keys as shields.
- Thralls in Soul Reaver 2, technically undead, shared the same skull-soul as Demons.
- Thralls are noted as "undead warriors" who are "charged to eternally guard Nosgoth's ancient shrines"[Soul Reaver 2 manual][Soul Reaver 2 strategy guide (Prima)] but the method of their re-animation is not elaborated. Given the places they guard, it would seem likely that the Thralls were Ancient vampire creations, though the thralls themselves, although humanoid, do not visually appear to be Ancient Vampire remains[Soul Reaver 2]. In Legacy of Kain: Defiance, similar Ancient Vampire locations would be protected by Feral Humans and the similarly 'animated' statues Vampire Golems and Guardian Constructs [Defiance][Defiance strategy guide].
- Historically, Thralls were slaves in the Viking age of Scandinavia (and the root of the word "enthrall").
- Similar "Thrall" enemies, arguably inspired by the same concept would later appear in Crystal Dynamics' Tomb Raider: Underworld, where 'Thralls' were undead enemies raised by the liquid "etir". These thralls had a notably similar appearance to Legacy of Kain thralls; with the "Viking Thralls" in that game sharing particular traits with the Swordsmen thralls of Soul Reaver 2.