There has been more than one Doctor in the WildStorm Universe. There have been Doctors (or shamans) since the very beginning of human thought. There can only be one at a time and each one is stronger than the last. When one becomes a Doctor he becomes a shaman charged with the protection of the planet.
The first Doctor publicy know as a superhero was never know by other name then The Doctor. He was the sucessor of the Evil Doctor holding the title of World Shaman and the predecessor of the two Doctors that have been members of The Authority: Jeroen Thornedike and Habib Ben Hassan.
The original Doctor was created by Warren Ellis and Tom Raney. He did first appeared in Stormwatch #48,
StormWatch: Change or Die
The first Doctor was a member of a superhero group called The Changers, led by The High. This group of heroes operated on the same principle as their spritual successors, The Authority, that there should be a better world. Unfortunately The Changers weren't as heroic as The Authority and often viewed as Anti-Heroes. Many of The Doctor's feats were chaotic and anarchistic in nature, though it could be viewed that everything he did was for the right cause, just in the wrong way. These feats included drugging the entirety of London with the hallucinogen DMT (Dimethyltryptamine, a powerful hallucinogenic mind altering drug with properties including intense hallucinations, euphoria and perceived extensions of reality).
The Doctor was finally killed by a hammer strike deep sanction missile with a payload of Biological Acid. After his death, The Doctor is often seen in the Garden of Ancestral Memory, where the Doctor (Jeroen) frequently goes to receive guidance from the previous doctors. He is the Doctor most seen in The Garden along with previous Doctor's such as Jesus, Albert Einstein, Isaac Newton and others.
Even after his death, however, the first Doctor still was a constant presence in the Wildstorm titles. As his death had catapulted to an astral existence in the Garden of Ancestral Memory, there he often gave counsel to his successor. However his attittude toward Jeroen it was not always that friendly, questioning constantly the wisdom of some of the actions taken by Jeroen, but still expectant on the developments of his successor.
The Authority: Revolution
After the Authority gave a Coup d'Etat in the USA and had to renounce to the control of the country after the rise of Paul Revere and his Revolutionaries, the Doctor still residing in the Garden was visited by a young Jenny Quantum who wised to talk to Jeroen, who had died recently. The Doctor revealed to Jenny than the spirit of Jeroen had ascended to the Garden and the Doctors were really disturbed by that event, as they had noted also than the successor had already manifested but it was absence of their contact. This motivated Jenny to reunite the Authority members in a rescue mission after discovering than all these events had been orchestrated by Henry Bendix, who had gained access to his own shift-ship.
After the Authority freed Habib, the spirit of Jeroen reunited with his mentor, replace him as the guide to the new Doctor.
End of the World
Whne the events of the number of the beast unleashed the end of the world in the Wildstorm universe, the doctors lost their connection to Habib. After a long time, Voodoo of the Wildcats with the help of other dead Doctor wascapable to summon all the previous Doctors, including Jeroen's Mentor, to help against the mad Jeremiah Cain. After Swift was designed as the new Doctor, he, along with his colleagues helped to heal the young Gaia Rothstein, a century baby transformed in a colossal monster for the rage born from the pain of the dying earth. When Gaia was healed, the Doctor returned to the rebuilt garden.
Powers and Abilities
Each Doctor has the combined knowledge and abilities of all the Doctors before him and the power to alter reality as long as he can imagine what he wants to do in "poetic terms". The Renegade Doctor described how his powers worked by saying that all he had to do was "draw a detailed picture in his mind" of what he wanted and it would happen. According to the previous Doctors that Jeroen has talked to, there seems to be no limit to what he could do. He could de-create the universe from the Big Bang to the end of time or stretch one moment to infinity if he wanted. There's a reason he generally doesn't use his powers on that kind of scale though. His powers come from the Earth and very powerful acts of magic can be harmful to
the planet (for example, he brought the immortal Jenny Sparks back to life at the cost of one year of the planet's life), so while the Doctor can do anything, he rarely uses his powers to their full potential. His relationship with the Earth is more than just the planet supplying him with power. He can feel how it feels and has a deep connection with it that is spiritual, emotional, mental and possibly physical. When Jeroen first became Doctor he complained to the previous Doctors that he had a pain in his heart and one of them told him, "The world now turns where your heart used to sit. A certain amount of pain is to be expected." Anyone with the power of the Doctor receives 15 new senses which, among other, unnamed things, allows them to not only connect with the planet, but with its people as well. At least one of the senses has something to do with an altered perception of how time flows, allowing for its manipulation, the ability to travel through it in more than one direction, move outside of it, and function at speeds different than the world around the Doctor.
Doctors can also go to a place called the Garden of Ancestral Memory where they can talk to their predecessors.
An alternate version of the original Doctor appeared in Stormawatch, as member of the team Stormwatch from a parallel universe, where the Weatherman was Jack Hawksmoor. and they never had make contact with any alien civilization. The team of this reality received help from the main Wildstorm universe through the Bleed to defeat alien invaders at the cost of their lives, including the native Doctor.