Expy: He seems to be obviously inspired by Elric of Melniboné, as both are tragic Magic Knights travelling between worlds, and whose weapon of choice is an evil greatsword harbouring an Eldritch Abomination, which feasts on souls of its victims and can make its wielder go berserk during a fight.
Despite the similarities, Word of God states that the creator of the campaign had never heard of the The Elric Saga prior to creating the character of Soul Reaver. Any similarities to Elrics, living or dead, are purely coincidental.
Who Wants to Live Forever?: In the background - while too well-meaning and not fatalistic enough be Driven to Suicide, Soul Reaver by no means really enjoys having become an immortal. Although he tries to avoid it, having once been mortal, he still (in spite of himself) forms emotional attachments to the comparatively fleeting things around him, inevitably leading to an eternity of loss. But it doesn't stop him from continuing on trying to help.
Our Vampires Are Different: other than displaying the traditional vampiric immortality and thirst for blood, seems to have few of the problems that other vampires do. Sunlight, for example, doesn't seem to faze him one bit.
Tainted Veins: When he is eventually met by the Companions in the final chapter, Morganem ingame model is sickly pale with black veins on his face. It is probably a consequence of his possession by Uthurak, as during the prologue Morganem uses an unaltered Kael'Tas model.
Mighty Glacier: Kherek, without a doubt. He's hard a nails and hits like several tanks strapped together. The fact that he moves slowly is pretty much the only reason why Kitharsis can defeat him in a duel.
Nietzsche Wannabe: Maelstrom, who thinks as a result the sole purpose of mortals is to benefit the everlasting Immortals.
Mechanical Monster: Without question. A towering, spike-covered tank that hurls explosive pillars and balls of chaos fire, spontaneously ignites anything that comes close, teleports in constant reinforcements, and to top it off, is barely scratched by most attacks.