The Omniversal Spectrum (or simply "The Omniverse") is the center of all reality - housing every universe, multiverse, etc.
At the center of the Omniversal Spectrum is a device known as the Glory, which keeps the Omniverse's structure whole. The device itself is directed by a living consciousness (an 'inheritor') whose life is extended to near eternity but still remains finite.
When the current inheritor's life begins to end, a replacement must be found. In order to do this, a gatherer (this can be the current inheritor or another life-form) must find and collect together two adversaries who are alike - yet polar opposites. The adversaries must then battle each other, with the winner becoming the Glory's new inheritor. This must be done, or all of existence will be at stake.
InformationEditAs the current inheritor - Esterath - neared the end of his time, he began his personal odyssey to search for the two adversaries needed to compete against one another - with the winner of the two becoming the new inheritor for the Glory. Coming across the dying essence of the Master while aboard his world-ship, Primus, Esterath sustained the Master's essence. The Master (who had been consumed by the Eye of Harmony inside the Doctor's TARDIS and spat out into the time/space vortex) proceeded to reveal his battles and undying hatred for his adversary - the Doctor - and held nothing back.
Esterath, believing the Master may be the one who he's searching for, shows him the Omniversal spectrum - with the Master bearing witness to the totality of existence. Some time later, Esterath placed the Master into the body of a recently-deceased old man in Brixton, London, while Esterath tried to find the Doctor. However, due to part of the Master's essence infecting the Doctor's TARDIS when he was devoured by the Eye of Harmony, he was able to form a symbiotic bond with it and thus change its destination as the TARDIS would now obey only him. As well as using this newfound power to 'teach the Doctor a lesson' by changing his destinations, he also used it to keep the Doctor away from Esterath - believing that since he and the Doctor were the adversaries who would do battle - he would need every possible advantage to defeat his 'old friend'.
While keeping the Doctor away, the Master tricked the immortal samurai Sato Katsura (who had unintentionally been made immortal and immune to pain by the Doctor during one of his and Izzy's adventures) into his service. Making Sato think he was on a holy quest, the Master gave Sato a 'holy book' known as the Odostra, for the 'Church of the Glorious Dead' (which the Master had written and which fantasized the Glory as a God). However, the Master removed the last page - with the intention of giving it to Sato when he was ready to implement it. In the years that went by, Sato and his forces fought and won numerous holy wars - with Sato becoming the undisputed monarch by the 19th Century - Earth united under one religion and renamed Dhakan. By the 20th Century, Dhakan had achieved interstellar travel and began to spread its doctrines to other worlds - with the Master (who had simply watched through the centuries) returning to give Sato his blessing and renaming him 'Cardinal Morningstar). Although a strict religion, The Church of the Glorious Dead never attacked other worlds.
Sensing the time was now right, the Master hid the final page in the Salius Cluster - where it was discovered by an archaeological expedition from Paradost. Dhakan's scientists would later confirm its authenticity - with Cardinal Morningstar arriving on Paradost to collect it in a special ceremony. The Master promptly changed the destination of the TARDIS again to lead the Doctor, Izzy and their new companion Kroton to Paradost to witness the event. Some time after, however, Cardinal Morningstar addressed his people on Dhakan - stating that the final page is for him and his believers to make an example of Paradost by destroying it. Unleashing a Dhakan war fleet and swarms of creatures known as the Ash Wraiths, Paradost came under heavy fire - with the Ash Wraiths forming a barrier to prevent outside help from getting in. To prevent the Doctor from leaving, the Master once more stole his TARDIS - leaving the Doctor and his friends stranded.
It was here, however, that Esterath finally caught up with the Doctor and took him away. Showing him the Omniversal Spectrum and explaining some of the situation, he takes the Doctor to Dhaken to learn the rest from his adversary. The Doctor soon realizes Dhakan is Earth and realizes the Master is responsible - with the Master soon appearing with the TARDIS and revealing what happened to him following his and the Doctor's battle in San Francisco and the events that led Earth to become Dhakan - before finally revealing that he and the Doctor must battle to become the new inheritor for the Glory. Although the Doctor doesn't want to give up his corporeal existence, he accepts that he must stop the Master from becoming the new inheritor and accepts the challenge. Esterath transports them both to the Omniversal Spectrum - giving them equal powers (although the Master has more experience). This soon shows as he quickly overpowers the Doctor and nearly defeats him quickly.
Thanks to his positive attitude and remembering that both he and the Master have equal powers, however, the Doctor manages to fight back. During the battle, the Master constantly hammers at the Doctor's mental and emotional defenses - claiming how both of them left Gallifrey on the same day for the pursuit of power (in one form or another). He also gloats about how when he defeats the Doctor, every square inch of reality will be his to control. The Doctor, however, retaliates that the Master couldn't even organize a decent end of term party during their university days - declaring that he and the Master are nothing alike.
The Doctor continues by declaring he is sick of the Master's twisted vision and callousness as well as having to run around and 'clean up' after the Master's numerous schemes - stating that people matter, regardless of their species (due to the Master referring to humanity and other species as 'lesser races' or 'animals'). The Master, however, counters that he and the Doctor have 'masqueraded' as Gods for centuries - adding that that Glory could solve every question the Doctor ever wanted to know. Declaring his belief that the Doctor wants the become the inheritor as much as he does, the Master screams at him to admit it.
The Doctor does admit he wants it, but that means he deserves it no more then the Master. However, the Master uses the opportunity to breach the Doctor's defenses and impale him with his blade - winning the fight and gloating over his victory, as well as inhibiting the Doctor's energy to stop him from regenerating into a new body. Bringing the Doctor with him, the Master begins his return to Dhakan to prepare for his 'impending Godhood'. Back on Dhakan, however, Kroton has been battling Sato in a pitched battle - in which Sato appears to beat Kroton. However, he is confronted by Izzy - who uses a Mnemonic crystal to share the pain she felt from been stuck on Paradost for three weeks as the Dhakan's destroyed the cities and slaughtered the numerous species. The realization that what the Master taught him was a lie and that everyone is alive proves too much for Sato, who collapses in despair. Izzy then gives the crystal to Kroton, who remembers his past life with his wife and children before he was converted into a Cyberman. Although Kroton states it hurts that he can finally see all that he lost, he admits that seeing what he had was very sweet too - with him thanking Izzy.
Their happy moment, however, is interrupted by the arrival of the Master and the dying Doctor. The Glory soon appears, with the Master intending to enter it and become the new inheritor of the device. However, the Master is shocked when the Glory rejects him. Esterath quickly explains his realization that he was never the gatherer and that the Master and the Doctor weren't the adversaries. Instead, he points out that Izzy was the true gatherer and that the two adversaries were Kroton and Sato - with Kroton been the winner as he has held onto hope while Sato has fallen into despair. The Master - angry and in denial - tries to destroy Kroton, but Esterath removes his power and his existence inside the TARDIS.
Esterath instructs Kroton that he must act now for the sake of everything, to which Kroton agrees. Hugging Izzy, he says his goodbyes to her and the Doctor - who again apologizes for shoving the high voltage cable into Kroton's chest during their first meeting. Having said his goodbyes, Kroton enters the Glory. Upon entering, Kroton uses his new powers to restore Earth back to normal, heal the Doctor, banish the Master and give Sato what he always wanted - an honorable death. Following the events, Esterath bid the Doctor and Izzy farewell - stating his journey had ended but that theirs had barely begun. When Izzy questioned the Doctor about if they would have a 'guardian angel' of sorts looking after them now that Kroton had become the Glory's new inheritor, the Doctor replied that he doubted it as Kroton would have a lot more to deal with then their little adventures.
Doctor Who: The Glorious Dead - Comics