The Voices (also known as Fviji) are a vast group of body-hopping personalities that all act as agents for The Armada. They can only control one body at once, but are immortal in every sense of the word. Neither time nor weapons can kill them.
There are over a thousand voices that will all control a single host at once, resulting in a host's activities seeming completely random. The best comparison I can think of would be Red in Twitch Plays Pokemon.Upon taking over a person, the host will begin to make seemingly random actions in an attempt to meet some kind of goal.
The Voices seem to worship a fossil called The Helix Fossil, and they will often mention it whenever something good happens. Their personal goal seems to be finding The Helix Fossil and somehow reviving it.