In the centre of things, in the centre of the web of cause and effect, a creature squats in a dark and almost dormant orrery chamber and sends its disembodied consciousness out to watch. It likes to watch. It sometimes likes to pretend it is actively participating, interacting directly with the forces it set in motion so very long ago, so many years ago, in the small and self-enclosed System it has made inside its prison. But it can only observe, and to a minuscule degree influence. It can only squat and watch.—The Sixth Chapter (Page 51-61)
The Charon is a major antagonist within Dave Stone's Doctor Who novel Sky Pirates! or the Eyes of the Schirron.
Character[]
The last member of its species, the Charon manipulated many of the events within the System through the power of the observer effect to return the "Eyes of the Schirron" to its clutches to begin a rebirth cycle. Due to being in isolation for thousands of years, the Charon became suicidal. It deeply hates all of the Time Lords.
As a member of the Charon species, the Charon had the ability to warp reality around itself. This let it create various constructs and form the System. By the time of Sky Pirates!, its abilities had weakened so much that it was effectively trapped within the System.
History[]

The System's sun, in which the Charon lurked
While the universe was still young, the Time Lords began hunting down and exterminating any species which could threaten their hegemony over reality. One of the species chosen by the Time Lords were the Charon due to their ability to warp reality. While most of the Charon were wiped out, one managed to escape and formed a small pocket reality along with the Eyes of the Schirron before lurking within its Sun. At first, the Charon inhabited the System with its various horrible monstrous spawn but over several thousand years these beings were killed by the other inhabitants of the System. The Charon also created several artifacts and vessels - with one of these being the Schirron Dream.
Around this time, a rogue planet named Planet X entered into the System. It was inhabited by a shapeshifting race known as the Sloathes who began to ransack the System. Wishing to rebuild the System, the Charon began using the observer effect to manipulate events to bring the Eyes back into its clutches. This would begin its rebirth cycle but would also destroy the System.
At first, the Charon watched over an Anean Seku named Leetha t'Zhan as she began her quest to find the Eyes. When Leetha (alongside Nathan li Shao) was threatened by a Sloathe captain, the Charon threw a piece of detritus it found nearby the System at this captain. This detritus just happened to be the Doctor's TARDIS - which (ironically) had been grievously damaged by a Charon reality bomb. While Leetha, Nathan, the Doctor, and Bernice Summerfield began looking for the Eyes in the Schirron Dream, a Serean criminal mastermind named Solan convinced a high-ranking Sloathe named Sekor Dom Sloathe to look for the Eyes with his help.
While on Aneas, the crew of the Schirron Dream unknowingly killed the very last of the Charon's spawn. This was closely followed by them being captured by Solan and Sekor on Elysium. With all four of the Eyes in their possession, Solan and Sekor travelled to the center of the System's Sun and brought it to the center of the Sun. The Charon rewarded this act by killing them. This was closely followed by the crew of the Dream (minus Benny) arriving in the Sun. The Doctor set about sabotaging the Charon's "orrery" but he was attacked by the Charon - which begin stripping away his various forms. Unbeknownst to the Charon, this simply made the Doctor stronger and stronger until he grew tired of this and asked the Charon what it really wanted. Though it is left ambiguous what actually happened, this ended the Doctor mercy-killing the final Charon.