Konami names six bosses in Belmont's Curse. Three are returning Castlevania characters, two are new to the series in this game, and one is a fixture of Dracula's castle. Every one of them has an official description and a credited voice actor.
The six, with their official descriptions
| Boss | Official description | Voice actor |
|---|---|---|
| The Fallen | A mysterious monster that stalks Paris, and the first threat Rose meets in the undercity. | Ray Chase |
| Joan of Arc | The French heroine of the Hundred Years' War, said to have been inspired by God. | Erica Lindbeck |
| Medusa | A serpent-bodied monster whose gaze turns countless people to stone. | Melique Berger |
| Isaac | A devil forgemaster who casts and commands demons, with a connection to Trevor from twenty years ago. | Liam O'Brien |
| Carmilla | A noble vampire waiting inside Dracula's castle, whose grace and combat stance are described as both terrifying and beautiful. | Dawn M. Bennett |
| Death | Dracula's right hand, carrying a soul scythe capable of cutting through space itself. | Aaron LaPlante |

What is actually new here
Joan of Arc is the surprise on the list. Castlevania has used real historical and religious imagery before, but a French national figure from the Hundred Years' War appearing as a boss is new for the series, and Konami frames her around divine inspiration rather than monsterhood. The official art places her kneeling on a burning rooftop with a greatsword planted in the stone.
The Fallen is the one with the least information. It is described as a mysterious monster rather than named as a historical or mythological figure, which suggests the story treats it as something the characters do not understand either.
The returning four carry history with them. Isaac is the thread back to Curse of Darkness, twenty years before this game, and his grudge against Trevor is stated in his own official description. Carmilla is placed inside Dracula's castle, which makes her encounter a location rather than a side fight. Medusa and Death are the two names the marketing leans on hardest, and both show up in the trailer footage.

What Konami has not published
Three things that almost every boss page on the internet will try to tell you:
The fight order. There is no published sequence, and the numbering in fan write-ups comes from inference rather than a source. Where each fight happens. Only two locations are implied by official text: The Fallen in the Paris undercity, and Carmilla inside Dracula's castle. * Which Arcana each boss drops. Three mappings have been described in hands-on previews, and those three are on the Arcana page with the source they come from. The other three are unknown.
The mechanical side of the fights is covered on the gameplay page, including how boss defeats convert into the Arcana system and how relics from optional challenges feed into the same build.
⚠️ Two extra names exist in community sources. Fandom's boss category adds a Succubus entry that Konami's character page does not mention. It is not included in the list above because the official page is the only source for who counts as a boss. It may well be accurate; it is simply not confirmed.
FAQ
How many bosses are in Belmont's Curse?
Six have been named by Konami: The Fallen, Joan of Arc, Medusa, Isaac, Carmilla and Death.
Is Dracula a boss?
He is listed among the principal characters rather than on the boss line-up, and the six named bosses do not include him. His role in the endgame has not been described.
Which bosses are new to Castlevania?
The Fallen and Joan of Arc. Medusa, Isaac, Carmilla and Death are returning series characters.
In what order do you fight the bosses?
No order has been published. Any numbered list you see is someone's inference from trailer footage.
Who voices Isaac?
Liam O'Brien. The full cast, including the principal characters, is on the characters page.