Before time was recorded, the being known as the Death Scribe penned the history of the future. His efforts culminated in the three Books of the Dead, volumes which prophesied the coming of a man known only as the Undertaker who would one day gather all three Books of the Dead and rule the darkest depth of Hell known as Stygian - Hell's prison where the most vile, disgusting souls were remanded after death. As a child, it is rumored that the Undertaker served time in the Stygian himself, for a crime yet unrevealed. During his time in the dark realm, the young Undertaker became well versed in the ways of the occult and evil things. The Embalmer was the first to cross the barrier that separates the Stygian from the mortal realm, stealing one of the three Books of the Dead while he was there. Whether or not the Undertaker was present in the Stygian at that time is unknown.
The realm was sealed following the Embalmer's transgression, but was opened again by Paul Bearer, a sadistic prison doctor who had learned the arcane secrets of re-animation of the dead. Learning of the realm and its powerful book, Bearer stole the second Book of the Dead. Again, why, how and if the Undertaker allowed this to happen are all unknown.
Both Paul Bearer and the Embalmer know that by possessing all three books, one can call down the end of all things, at which time, the powers of the universe would be free for the taking. Motivated by their utter lust for power, the Embalmer and Paul Bearer will stop at nothing until they posses all three books.
As part of this plan, one of the two surely was responsible for imprisoning the Undertaker in the early part of this century, a move that left Stygian ripe for the picking. With the Undertaker gone, the Embalmer and Paul Bearer tore the order of Stygian asunder, creating warring factions of Dark souls loyal to either Bearer or the Embalmer, and taking legions of Dark Souls to serve as their earthly troops.
Ultimately escaping from his prison, the Undertaker returned to Stygian, where he has been fighting to maintain order. Bearer and the Embalmer realize that they could never take Stygian while the Undertaker resides there, so they have moved their battle to the earthly realm. There, they use the ring of the World Wrestling Federation as their battlefield; pitting Dark Souls disguised as human wrestlers against one another. As one wrestler defeats another, the defeated Dark Soul returns to Stygian, leaving its master that much weaker and more vulnerable to personal attack from the other.
Since entering the WWF, fans looking for darker heroes have embraced the Undertaker, Kane and Paul Bearer. The fans have even given them background stories that hint at the truth, such as the fact that the Undertaker and Kane are brothers, and that Kane was horribly disfigured in an accident, but other stories, such as Paul Bearer being Kane's father are the fiction of storytellers.
If the crowd knew the real truth behind these wrestlers, they would certainly run for their lives and their souls. The effects of a human knowing the actual truth can be seen in Mankind, a wrestler who sees the Dark Souls for what they are, and that knowledge has contributed to his madness.
In both his days in the WWF and in Stygian, the Undertaker keeps his own counsel, rarely speaking - the picture of a driven, obsessed man. His determination to complete his task at hand and send all the Dark Souls back to the Stygian is like his presence in the ring - utterly unstoppable. He has been compared to a force of nature by some, a very valid comparison. Truly he is a force not to be reckoned with.
His path and mission clear, the Undertaker has his eyes set on his goal - the championship belt of the WWF. By ultimately defeating all his enemies in the WWF, and gaining the championship belt, the Undertaker will have vanquished the Dark Souls of both Bearer and the Embalmer, robbing them both of their armies and power, a move which will allow him to regain the two Books of the Dead. With all three Books, the Undertaker will reign as the ruler of Stygian and return order to his realm. If the Undertaker loses the belt, then all will be lost.
Do not be fooled - the Undertaker can take no comfort in the words of the Death Scribe, that one day he will rule Stygian. For while the Books reveal the final destiny of the Man from the Dark Side, they say nothing about the trials, tribulations and Hell he has to pass through to reach it.