From Game Text:
You are a predator: a vampire who stalks human prey in the night, feasting on their blood.
Blood is life. It’s eating, drinking, breathing, and fucking, all wrapped up in one little, crimson drop. Your thirst for blood is blinding and drinking it – that’s ecstasy. Feeding from prey isn’t just sucking on a juice box; it’s going to a fine restaurant.
You will go to any length to feed. The craving to do so is ever-present. Even when you swallow your fill of blood, the devil whispers in your ear, tempting you to drink more. Go hungry and the beast takes over. The beast is the relentless beating in your lifeless heart; it craves excess, cruelty, and destruction. When the beast wins, you lose your free will and devolve into a mindless monster. Your humanity – your connection to what it means to be human – is the only thing that holds the beast at bay, and it is a flickering flame in the windswept darkness. Between feast and famine, restraint and recklessness, a predator’s unlife offers more than an eternal, blood-junkie existence. Immortality is the reward that awaits a predator who can balance on the knife edge.
Predators are the apex: the union of man’s scheming ingenuity and beast’s instinctive ferocity. Though man and lesser creatures are sheep to the wolf, the wolf is among a pack of wolves. And in this pack, the most cunning and ruthless is the alpha. All predators envy that power and prestige. They nip at each other nightly, fighting over the scraps. Each hopes to one night rule the pack. Thus, from the greatest predator to the least, all are embroiled in a ceaseless conflict of intrigue and bloodshed.
This is what it means to be a predator. This is Undying.