"Despicable. You deem yourselves worthy of a challenge? Allow me to educate you on your folly." - The Voice of Enmity.
As the name implies, creatures of unknown origin that are in charge of operating the Trials of the Citadel, which is used by many people to escape the Depths and return to the surface "safely".
They operate the Trials of the Citadel within the Citadel of Celtor, where, if players showcase their strength by defeating an opponent, they are returned to the surface.
Currently, 4 voices are operating the trials: The Voice of Authority, The Voice of Sequestration, The Voice of Odium and the Voice of Enmity.
Each voice acts differently from the other as their name suggests. While the Voice of Odium and Enmity show general disgust and hate towards the player, the Voice of Sequestration finds a "particular" interest in the player.
Very likely to have an unknown hierarchy where the Voice of Authority rules over the rest of the voices, as it has the final say in every trial.
Depending on the strength of the player when they show up to the trial, they would put either a very difficult enemy to fight the player, such as the Enforcers or Nautilodants, or let them go without a fight if they are too weak.
Their current goal is to sacrifice the souls of strong people to "Their Master Below", where is possible that when they die in the trials, their souls are sent to their master in a deeper layer. However, sometimes they use said souls from the ones who perished in the trials to create the Enforcers. -Their "Master Below" is suspected to be the creator of the Voices of the trials, where said master is supposed to either be a being of great power, or maybe an unknown Drowned God that resides within a deeper layer. -Since they only show interest in those that are "Fit for crushing" (AKA Strong players), it is most likely they use the souls of those weaker who perished in the trials to create the enforcers, and those who are stronger as a sacrifice to their master.
Each Voice has a physical representation where they can be defeated such as the case of the Heart of Enmity being the physical form of The Voice of Enmity. However they only fight with their physical form when they deemed so, such as the case of Enmity where he decides to fight the player when 5 or more people are brought into the Trial, as Enmity sees it as "Making a mockery of this place with sheer numbers", and wanting to punish the player.
However, while being able to be defeated,d they are very powerful beings where probably one entity is stronger than other, such as probably being the Voice of Authority the stronger of the Voices.