The Belmont Family serves as the primary protagonists of Castlevania, with each game focusing on a different generation of Belmonts in their war against Dracula.
However, despite being the central characters in the saga, the best games in the franchise consistently are the ones where the Belmonts are either sidelined or exist only as unlockable characters.
Source: N4G PC Castlevania Is at Its Best Without the Belmonts