The Underworld was a unique Prime World that stood above many Prime Worlds in terms of power. This was why even though many powers were surprised when they saw the name of a Vampyre Prince shine brightly on the leaderboard for the Infernal Hunt, they understood it as a fact when they connected this Prince to the Pureblood Vampyres of the Underworld.
It was a powerful world that was filled with unique monsters and powerhouses, ranging from the Vampyres, to Werewolves, all the way to the race of Cyclops and other unique creatures.
Out of all the organizations that were distributed across the wide Underworld though, the Vampyres were the most powerful, and the most secretive. They mostly kept to themselves as they continued to expand their lands and power, eventually becoming the known dominant force of the Underworld.
