During your adventures through V Rising you should come across a mission known as Blood Hunt, this mission will involve a Blood Altar.
Using this Blood Altar we will then be given the opportunity to hunt down various different V Blood bosses. These bosses unlock a bunch of new rewards including new abilities, making them an interesting set of missions to undertake.
Below is a list of these V Blood bosses and where to find them. There are quite a few to find, all of which are listed within the game.
V BLOOD BOSS LOCATIONS
Solarus the Immaculate