Castlevania: Curse of Darkness is an action-adventure game, part of the Castlevania franchise. It is the second 3D Castlevania title developed by Konami Computer Entertainment Tokyo following Castlevania: Lament of Innocence and was released for PlayStation 2 and Xbox in all regions except Japan, where the game was only available on PlayStation 2. Curse of Darkness received mixed reviews, common praise was directed towards its combat system, music, content, and replay value, while criticism fell towards its story, characters, repetitive level-design and gameplay.
When the game begins, Hector arrives at an Abandoned Castle to confront Isaac. The latter scoffs at his desire for revenge and dares him to regain his powers so they can settle their score in a satisfying way. Hector reluctantly accepts the challenge, and starts hunting his former friend across the Transylvanian countryside. During his quest, he encounters several people: Julia Laforeze, a young witch in exile who turns out to be Isaac's sister, Trevor Belmont, who distrusts him for being a Devil Forgemaster, Zead, a kindly holyman who provides him with reliable information about Isaac's whereabouts, and St. Germain, a mysterious time traveler who presses him to abandon his quest, but eventually leaves him alone with some cryptic comments about a "new destiny" having emerged for him.
At one point, Trevor decides to trust Hector, and uses his own blood to unlock a parallel world called the Infinite Corridor, where Isaac is supposedly hiding. However, when Hector fights a Dullahan there, an evil glyph channels his energy and uses it to summon a new incarnation of Dracula's castle. Isaac, who intended this all along, cruelly stabs Trevor and leaves him for dead.
Hector enters the new Castlevania, where he fights and defeats his nemesis. As he prepares to kill him in a fit of rage, he suddenly remembers Julia, who had warned him not to let the Curse take hold of him. Horrified, Hector realizes that his actions are being controlled by Dracula's Curse. A triumphant Zead appears and confirms this, explaining that the Devil Forgemasters were supposed to fight to the death, with the blood-stained Hector becoming the vessel for the Count's reincarnation. Having secured Isaac's body for this purpose, he reveals himself to be Death and attacks, in vain. Hector proceeds to fight Dracula, who is unable to take full control of Isaac's body and returns to the afterlife. Hector then uses his powers as a Devil Forgemaster to lift the Curse. Julia comes to his rescue, and they start a new life together. Meanwhile, St. Germain departs for the distant future, wondering how the struggle between mankind and Dracula will end.