Hector’s reference is the Forgemasters from the Castlevania fictional universe

Castlevania is an American adult animated dark fantasy action streaming television series on Netflix. Based on the Japanese video game series of the same name by Konami, the first two seasons adapt the 1989 entry Castlevania III: Dracula's Curse and follow Trevor Belmont, Alucard, and Sypha Belnades as they defend the nation of Wallachia from Dracula and his minions.

Hector (ヘクター Hekutā) is a major character in the Castlevania animated series, serving as one of Dracula's two human generals in his army (the other being Isaac). He is a Forgemaster who uses a hammer to bring humans and animals back from the dead and to call demons from Hell into corpses; the resulting creations become newly living monsters that can be enlisted in Dracula's army, loyal to Hector's intent.

A Devil Forgemaster (悪魔精錬士 Akuma Sērenshi) is a human trained in the dark arts and, akin to their namesake, bears the ability to create and forge demonic and wicked creatures.

Mainly known simply as «Forgemasters» instead of manifesting Innocent Devils from pure darkness, the main way both Hector and Isaac are able to utilize their magic is by performing rituals with special tools, either to bring people and animals back from the dead or to call demonic spirits from Hell into intact corpses, transmogrifying the bodies and turning them into creatures of the night in order to enlist them in Dracula's army. Their methods, however, seem fundamentally different: Hector uses surgical tools to prepare the bodies and then reanimate them. By bringing the dead man back to life, Hector gives his patient knowledge and powers.

This process appears to be similar to necromancy on the surface, but Hector explains that interpreting it as such fundamentally misses the point because the goal of forging is to create living beings: "He's not dead. We create life from death here." Indeed, Hector further explains that "night creatures" are species in hiding, able to increase their numbers in nature without the help of Forgemasters.