When something is dear to you, its effect upon you becomes immeasurable.
Then, for the Master, I'll feast on your soul this night!
~ Castlevania: Symphony of the Night
Death is the secondary antagonist of the Castlevania video game franchise, based on the Grim Reaper of folklore. The divine ruler of Limbo and dead souls who decides who dies and lives, he is Dracula's first and foremost follower and second-in-command and often attempts to resurrect him or serves as his last line of defense.
Death is a fallen angel who was condemned to hunt for souls for all eternity. Holding his silent grudge against God, he waited for the rise of the King of the Night. He shares characteristics with the Shinigamis (Death Gods) of Japanese Folklore, but he is the real Grim Reaper. In some games, there are minor Reapers that are implied to work under him.
As the harbinger of death, Death and Dracula are natural allies. Death would help anyone trying to revive his lord, and would wander through the land spreading death and sowing misery to make men's hearts hateful, so that their evil would bring Dracula back. He is stated to obey the wielder of the Crimson Stone, an alchemic jewel controlling souls in possession of Dracula, but their relationship is deeper that a mere bond to an artifact, and he is repeatedly described as Dracula’s closest friend and confident. He himself states to work with those who follow the calling of Chaos, to which he is bound.
In most games, he appears to be destroyed after his defeat, but he is never gone for real and it is implied that only his physical incarnation is gone, while his essence is sent back beyond the Veil, until he recovers. In Castlevania 64, he is seen forcibly expelled from the Earthly Planes and states that he will await his victor in Hell.
Death is absolutely loyal and takes great pride in working for Dracula, holding his lord in very high regards. This is notable when he is confronted to people coveting his lord's throne, as he finds the mere idea of the Castlevania being ruled by anyone else than Dracula "positively absurd".
Death is cocky and confident, but he never holds back against anyone, unless he sees a reason for this. He is cold, imposing and threatening. He never loses his composure and remains perfectly stoic, even when angered. He rarely works with other vassals of Dracula and prefers acting on his own. He also enjoys taunting and tormenting both his enemies and the dead souls in his grasp very much.
He harbours contempt towards the heroes, but no outright hatred. He treats them with harsh indifference or cold politeness following his mood, and only insults them when defeated or outraged. He acknowledges their merits nonetheless, and never hesitates to taunt the heroes whose power is not at its fullest, calling them a disgrace to their name. Moreover, he can prove honourable and respectful, willingly cooperating as long as their goals converge, though he insists that they remain enemies.
Death is a highly skilled manipulator, who often uses the heroes when he seeks the same thing (Ada and Lydie, in Legacy of Darkness and Harmony of Dissonance, Brauner's defeat in Portrait of Ruin). He lets them progress, even stealthily guiding them, before appearing to seize the prize. He can devise elaborate schemes to lead the heroes where he wants to from the shadows, but he rarely bothers, preferring to seize opportunities when they appear.
He has (or had) apparently a great deal of respect for Alucard, as he somehow bemoans the fact that he sides with mankind and seems reluctant to fight him. However, all the respect he could have for anyone would not prevent him to attempt to get rid of him or her should said person raise against Dracula.
Powers and Abilities
As expected of a minor deity, Death is extremely powerful. He has full control over Limbo, where he gathers all the departed souls under his command, which he can summon and do with them as he pleases.
He can cause demises; though he seems unable to do so with the heroes, having to attack them upfront. He masters magic and Dark Rituals, he can shape-shift and alter his aspect, seal people in coffins, rip souls from their bodies, and create images of himself. As a demonic chaotic being, he is resistant to Dark but weak to Holy.
His signature technique consists in conjuring never-ending waves of sickles to harass the players, that can intercept projectiles and must be destroyed to reach him. He also wields his huge scythe with immense proficiency and use death-themed attacks: Launching dead souls like rays or whirling blasts; conjuring tormented souls; hurling energy balls, scythes of energy or giant, ghostly skulls; causing huge explosions; and so on and so forth.
When defeated, he sometimes transforms into a more powerful skeletal monster to continue the fight.
Death usually has 4444 life-points in games, as the number four is linked to death in Asian superstitions.
Death shape-shifting as a human priest is a reference to Ingmar Bergman's classic film The Seventh Seal, in which Death does the same. Zead even looks just like Death’s representation.
Death being portrayed with wings in the N64 games might refer to the Angel of Death of Abrahamic religions.
In the cancelled game Castlevania Resurrection, Death rides a greyish-white horse in the sky, referencing his biblical role as one of the Four Horsemen of the Apocalypse. It also refers Gustave Doré's famous painting of said Horseman "Death on a Pale Horse".