"How many of those advanced Potions has the Demon King given you? I've slain countless Vampires before you, and yet you survive my deadly attacks, recover and continue fighting. You're like an Undead!" he exclaimed. "Potions? What Boss gave me is something far better than that," said Miles. The substance that he had been consuming repeatedly... was Vandalieu's blood, the main constituent of Blood Potion. It was no ordinary blood; it was the blood of a Demon King who had become a demi-god. Such blood had even greater restorative properties than if it were turned into Blood Potion, especially for an Abyssal Vampire. With the 'Bloodwork' Skill, it boosted the Attribute Values and stimulated the 'Rapid Regeneration' Skill. On top of that, it made the body's fatigue vanish as if it had never existed at all.