story identification - Sci-Fi book with 4 prison planets

I read a book once where an agent of a futuristic multi-planet government was sent on a mission, and in doing so, used a machine to impress copies of his mind on other people to send them.

I remember no names, of people or locations, but I can describe what I do remember.

The place the copies of this man were sent was a planetary system that was used as a prison. The planets were used as a prison because of a unique type of bacteria or virus that lived there. Whenever that bacteria would go too far from the planet, it'd die, and take any organism that it was inside with it. There were 4 planets in the system, and copies of this man were sent to each one. Each planet granted the copy one "power", unique to the planet, through the bacterium. In one world the bacteria would break down everything man-made remarkably quick, but some people could control them enough to stop, and even create things for you. Another gave people the ability to swap minds during sleep, waaking up into a different body altogether. A third gave the man "adaptive DNA", so to speak. He subconsciously would change his DNA to match the environment, which could've meant a sex change, if he lived in an all-male environment. And sadly, I dont remember the 4th well at all. I just know someone became a dragon at some point, and that someone was blind.

Anyway, I read this book at my high school library. That copy was a plain brown cover, no title or anything, and although the name was inside, I have forgotten it. I have forgotten it and the author and all the unique names to search for, and all my searching for the things in this description have yielded nothing. If anyone knows this book, please tell me its name, or anything that could lead to me finding this book again.

Answer

You are almost certainly asking about the Four Lords of the Diamond by Jack L. Chalker. From Wikipedia:

The Four Lords of the Diamond is a series of four science fiction novels by author Jack L. Chalker. Each volume of the series primarily follows a duplicate of a government agent as he lands on his prison planet and begins to both investigate the menace to the civilized worlds and find his position in his new society. The duplicates realize the stagnancy and corruption of the Confederacy, the intergalactic government in the series, and question their position as tools of the hierarchy. As the series progresses, the primary agent experiences each of his counterparts' divergent experiences and begins to question his beliefs as well. Like much of Chalker's work, the series deals with the effects physical transformations have on a character's personality.

Four prison planets being infiltrated by the protagonist, who is the agent of a government outside the system

Each of the planets' prisoners are kept there by an ubiquitous biological agent, the "Warden Organism," which dies (taking its host with it) if it ever moves more than a short distance from its planet.

Each planet—Lilith, Cerebus, Charon, and Medusa—has its own unique ecosystem, with the human population endowed with its own abilities and psychology.