IV Rising requires Greater Blood Essence and Blood Essence to keep your castle running. Here's how to get them both
V Rising Unsullied Heart Farm and Greater Blood Essence crafting recipe guide
All living creatures, such as deer, wolves, and humans, lose Blood Essence, but not the undead, such as zombies or your fellow vampires.
The blood essence is a drop from living beings. You will be able to hit F to feed them once they have reached a low enough HP level. This only takes a few seconds, and you'll get some blood essences depending on the creature's level.
Blood Essence is then used to power the Castle Heart in your base and upgrade practically everything else. To power key crafting nodes around your base, draw Blood Essence from your inventory to the heart.
