|“||If you want an easier way to get a vampire's power, just let one of them turn you. If you're not tainted yet, you should be all good. But Eaters are different. Fouled. Trying to gain all of a vampire's powers, but none of their weaknesses. If Vampire Hunters actually existed, they wouldn't be dhampyr like in those legends. They'd be people like her—quick-thinking, underhanded, and determined to the point of annoyance.||”|
Upon drinking the blood of just one vampire, Eaters gain the ability to sense nearby vampires, a power that actual vampires do not have. It appears that Eater-turned-vampires (such as Shizune Kijima) still retain this 'sixth sense' after they are turned. However, Eaters are unable to sense other Eaters. The act also causes the Eater's body to undergo a type of metamorphosis, acquiring enhanced speed and reflexes that make them seem closer to vampires than humans.
The more vampires an Eater consumes, and the stronger the vampires are, the more powerful the Eater becomes. However, an Eater's body is strengthened by their victims' power only up to a certain point: too much, and the power will eat away at their muscles and organs. Though most might not sense the pain at first, it can build up little by little until it overwhelms the individual. Notably, Eater Theresia Riefenstahl has been spared this weakness after The Organization saw the power eat away at Rudi Wenders.
Gerhardt von Waldstein has theorized that when an Eater devours the flesh and blood of a living vampire, they are obtaining the 'soul' energy that had filled the vampire's body. This is because "a vampire's blood is the catalyst that circulates the soul's energy through his body." Since a human's blood acts as an adhesive of sorts, a vampire who drinks the blood of an Eater who has just drunk another vampire's blood, the first vampire will gain that vampire's abilities.
In the Story
Eaters are utilized by both The Organization and its enemies, as evidenced when the Sunford Clan sent out a horde of over two-hundred Eaters to combat members of The Organization in Vamp! IV. However, since the Sunfords had only bothered to give their Eaters the blood of one or two vampires each, the Eaters were fairly weak and no match for the members of the Organization. In contrast, the group of Eaters who killed off the vampires in Alma's village were able to do so with ease, since those vampires had minimal vampiric abilities.