Alliance with the Daleks
As Guardian of the Solar System, Mavic Chen ruled over Earth and her dominions. He was also entrusted with the secret of the Great Clock, whose mechanism bent space-time, allowing spaceships to travel quickly across the Galaxy. However, Chen didn't like the Clock, especially because it was sustained on slave labour and he feared that an eventual discovery of this ugly truth would be something public opinion wouldn't be ready to accept. He then tried to find an alternative source of power. (AUDIO: The Guardian of the Solar System)
In 3950, he secretly commenced an operation to mine an emm of taranium, a mineral only found on Uranus. The taranium could power the Time Destructor. In 3975, he took part in the Non-Aggression Pact of galactic powers. To Chen, this alliance was merely a tool, a stepping stone on his inevitable rise to greatness and immortality as "First Ruler of the Universe".
In 3999, he read about the Daleks in a report written by Space Security Service android agent Mark Seven, who encountered them on M5 together with fellow agents Jason Corey and Sara Kingdom. (AUDIO: The Destroyers) Chen was particularly impressed with what he read about the latter. When Sara unexpectedly turned up at the Clock, while she was supposed to be on Venus on a six-month assignment, her brother, Bret Vyon, brought her to Chen. Unbeknownst to both men, this was a future version of Sara, just arrived in the TARDIS with the First Doctor and Steven Taylor, and knew about Chen's future alliance with the Daleks. Questioned about her presence here, she lied, saying that she wanted to know about the Clock. Chen then explained it to her, adding that he was dissatisfied with it and aimed to replace it for an alternative source of energy. He then asked her for advice. Sara, hoping to avoid his betrayal, started giving him some ideas, and Chen gave the impression of listening and taking her seriously. In reality, though, he was just testing her to see her potential. In the end, satisfied, he arranged for her to be promoted and moved from Venus to Earth as part of his staff; since he didn't know about this Sara having come from the future, he unwillingly promoted an unsuspicious, younger version of her. Later that day, when the Clock was destroyed, he managed to escape alive and unharmed. (AUDIO: The Guardian of the Solar System)
By 4000, he had developed a core of loyal underlings and allies such as his security chief, Karlton, and the staff of the Space Security Service, an elite corps based on Earth. He had even obtained the loyalty of Daxtar, the powerful friend of SSS agent Bret Vyon, who would later seek his help in opposing Chen. (TV: The Daleks' Master Plan)
Course of the alliance
In 4000, he travelled in his space vessel, 1-11 Spar, to the planet Kembel secretly to join the seventh meeting of the Galactic Council made up of himself, the Daleks and delegates of the Outer Galaxies. He plotted, meanwhile, to send a force from Venus to destroy the alliance and Kembel as soon as he had gained the Time Destructor. When the First Doctor and his companions succeeded in stealing the taranium from the Daleks' base on Kembel, Chen recruited Sara to help him. Chen had lied, telling her that Bret, who was helping the Doctor, was a traitor. Sara believed Chen and killed her brother. She switched over to the Doctor's side upon learning the truth.
When the Doctor attempted to escape in his TARDIS, Chen joined the Daleks in their pursuit of them through the centuries. Chen was able to retrieve the taranium after the Daleks caught up with the Doctor in ancient Egypt. Chen and his allies returned to Kembel, where he convinced himself that he was the equal of the Daleks and when the other members challenged him he killed Gearon, telling the remaining delegates that they would be allowed to govern their galaxies, directly responsible to the Dalek Supreme and himself. The Daleks pretended to go along with his plans but imprisoned him along with the others. The other delegates decided to escape and form an alliance against the Daleks.
On Chen's release, he destroyed his own ship in order to fake his death. At gunpoint, he took Steven and Sara to the Daleks' underground base in order to rebuild his alliance. He believed by now that the Doctor intended to forge his own alliance with the Daleks with the intent of betraying them. He attempted to give orders to the Daleks but, having outlived his usefulness, he was finally exterminated on the order of the Supreme Dalek. Quite mad by then and disbelieving the reality of his own death, Chen proclaimed he was immortal even as the Daleks' gunsticks fired upon him. (TV: The Daleks' Master Plan)
A message recorded by the deceased Marc Cory and found on the body of Bret Vyon exposed both Chen and Karlton's alliance with the Daleks. They were found guilty of high treason for which the sentence was execution. Karlton was arrested on Earth by Senator Diksen while a force made its way to Kembel to arrest Chen, although they would find only a lifeless planet destroyed by the Time Destructor. (PROSE: The Mutation of Time) The revelation of the Dalek alliance triggered the Great War. (PROSE: The Evil of the Daleks)
Despite Chen's betrayal of Earth and his extermination by the Daleks, he succeeded in founding a dynasty that controlled Earth and much of the galaxy for many centuries. (PROSE: The Crystal Bucephalus)
Nigel Colloon suffered from a delusion where he believed himself to be Mavic Chen, (AUDIO: The False Guardian) apparently seeing Chen as a figure of strength who would not have suffered the personal losses Colloon had. (AUDIO: Time's Assassin)
Vindictive and power-mad, Chen appeared to have no sense of ethics whatsoever. He refused to accept the Dalek Supreme openly breaking off their alliance with him. By then, he had convinced himself that they worked for him. (TV: The Daleks' Master Plan)