The Antediluvians are the founders of the thirteen vampire clans. They are attributed to be Vampires of incalculable power, each of whom survived the Great Flood. Presumably the Antediluvians are of such age and potency of blood that they possess nearly god-like power.
If the Antediluvians survive in the modern nights they must possess sufficient abilities to hide their existence and activities from the world, particularly considering the monumentous effort that has been put into locating their havens by Cainites of many different factions. As they are commonly believed to be directing the Jyhad, they must also possess an incredible level of influence or knowledge, and perhaps even the ability to manipulate those who bear their blood. In fact, blood lineage is often cited as a factor in an Antediluvian's power, and most assume that each is concerned most of all with their own clan. There are also some examples of ancient vampires bestowing portions of their power to other vampires, and while few of the ancients are described as being actual thaumaturgists, they seem to possess a great deal of versatility, which is evident in the various artifacts created by the clan founders.
Their society turned to violence and evil. By the time the Flood occurred, they had long since closed their eyes to truth and justice. This master-race of super-beings ruled their world and probably eliminated a large portion of the human population.