The world of Diablerie is set in a world adjacent to ours where vampiric lords of the night have lived in secret from us for some time. These lords have formed Families, vampires with similar manifestations of their affliction. In the different Families exist a parasite, always threatening to consume and take over their bodies. Those who have been completely consumed, the Anathema, pose a threat to mortal society and supernatural society alike as their frenzied assaults contain the full strength of the parasite unfettered.
A tentative alliance was formed between a group of young ambitious vampires whose goal was to unite themselves and fully conquer their parasite. They formed the Sovereign, a society that has stood until the modern day. Extending their Kindnesses onto the vampiric world, the Sovereign has taken uncontested reign over the night challenged only by those who grow too close to their parasite, the Anathema.