In Shyish, there is a mountain range, the Day's End Mountains, behind which the sun seems to be perpetually setting. One of these peaks, Mount Hadreth, stretches far above the others, its top obscured constantly in an unearthly fog even while the air becomes almost too thin to breathe. Near the summit, there is a door, and behind it a stairway said to lead deep into the heart of the mountain. From there- although none had walked the stair in many generations by the end of the Age of Myth- the passageway led to a series of massive caverns, stretching throughout the roots of the entire range. Taken together, the people of that region know this as the Tomb of Eternal Life, where souls are said to reside forever beneath the world of the living in society with one another.
It is forbidden that one of the living should enter the Tomb, just as it is forbidden that one of the dead should seek to exit and return to the living. But humans are weak creatures who cannot hold even to the rules they set for themselves. For this reason, the door must always be guarded, lest someone in their hubris might seek to be reunited with one they have lost. These eternal guardians maintained an unblinking vigil, keeping the door- already protected by mighty theurgy- safe by the strength of their arms and their faith in their cause.
This ended, though, like so many other things, with the coming of Chaos.
It had long been prophesied that when the end came, the guardians of the dead would descend to fight alongside the living. Thus, the commander of the watch, who was human despite her calling, led her comrades into battle against the great hordes of the Dark Gods at the foot of the mountain. For eight days and nights, the soldiers of the mountains struggled with legions of daemons and cultists, but the end should never have been in doubt. The door watch was wiped out to a soul, and the gate lay unguarded for many decades. During this time, though no mortal could yet penetrate the wards, daemons slipped in to trouble the dead, and malefic spirits came out to trouble the living. Thus was the balance of the world upset, until someone came to restore order to life and death again.
Rebecca grew up the daughter of a poor farmer, eking out a living in the foothills of the Day's End mountains. They lived constantly in the shadow of the Dark Gods- almost literally, since the followers of Chaos had built great iron fortresses on the heights to assert their dominion over the people below. Though they ruled the land, the overlords of the mountains contented themselves with their fastnesses, only sending out their tax collectors and enforcers to exact punishing tribute every few weeks. Thus, Rebecca's family was able to live in relative peace, and she was raised on the whispered tales of a time before enemies overran the mountains, when the heights were held by the guardians of the Tomb of Eternal Life.
Even as a child, she longed to see the gate that led into the tomb herself- but knew that she could not. The Gate had long since been fenced in by the sorceror-lords who had taken Mount Hadreth as their private domain. In this day, they ruled over her hamlet, and from time to time misshapen abominations would wander down from the mountains to snatch one or two of Rebecca's neighbors away for whatever purposes the sorcerers thought to put them to. Rebecca was plain, and quiet, and quick to run, and thus she evaded the overlords' "tribute". Still, it burned at her, as it would burn at anyone, to see her friends and relatives stolen so unjustly.She made a quiet vow that she would one day give retribution to the sorcerers for all they had taken from her and her people.
That day came sooner than she would suspect. In her seventeenth year, Rebecca was engaged to the love of her life, a farmer boy named Abraham. When the abominations came to exact tribute in the winter of that year, though, he tripped over a root- and was seized by one of the creatures. Filled with a mighty rage, Rebecca grabbed a pitchfork and attacked the beast, stabbing it again and again until it lay dead. Consumed with the same anger, her fellow villagers joined her, hurling stones and trash and attacking with whatever came to hand until the invaders were forced to retreat.
The village lay in a deathly quiet for two weeks- until news came that dozens of servants of the sorcerers, not just mutants but armored warriors, were descending to make an example of those who practiced defiance. There was nothing to do but flee. As nomads, living off of whatever they could scrape from the barren land, harried by sorcerous beasts, the villagers survived in hiding. As they went, they armed themselves with weapons from their fallen foes, striking back under Rebecca's leadership against individuals or small groups, repaying the sorcerers blood for blood. When the other villages heard of their continuing defiance, some among them joined Rebecca's band, while others sent food and supplies in secret for the fight against the hated masters. Soon, Rebecca's band had grown to number in the hundreds, menacing the sorcerer's servants whenever they came down off the mountain.
In response, the lords of the peak sent down their full strength, intending to punish the full region for daring to rise against the faithful of the Dark Gods. The might of the enemy's army was more than Rebecca's band could face in the open field, but desperation and cunning gave her a plan. Throughout the hills and ravines of that land, her warriors hid and struck at the enemy army as they passed. Where they could, they rolled boulders down on the heads of the enemy, crushing them or blocking their paths. They struck by night, poisoning food supplies, murdering pickets and setting fires in the brush and never, never coming to open battle.
While this happened the sorcerers rampaged blindly, driving villagers who had remained neutral out of their homes- and into Rebecca's arms. Others, hearing what happened, openly supported her lest the sorcerers should pillage their homes as well. By this her army grew strong and well supplied, while theirs dwindled and starved. When she finally met them in battle, it was a rout- her soldiers drove both abomination and man before them, slaughtering both those who stood before them and those who ran. With the army of the Dark Gods destroyed, all that remained to her was to overthrow the sorcerers themselves and cast down their fastness. Up the long mountain roads her army marched, fighting the daemons summoned against them until at last they came to the fortress itself. They had no siege, and they certainly had no sorcerers, but some among her troops knew how to work rock and dig stone, and it was not long before a breach was created.
The end was almost an anticlimax. Rebecca's forces slaughtered the sorcerers and their apprentices, tore down their workshops, gave a merciful end to their experiments, and made obeisance before the Gate itself. But the Dark Gods never forget, and never forgive, and soon she would find herself assailed again.
What Rebecca had faced to date, deeply personal though it might have felt, was akin to an autoimmune response- an angry red inflammation of the wound. On the scale of gods and empires, it meant almost nothing. Now that she had succeeded in toppling servants of any real importance, though, she had drawn malevolent attention. From all throughout the Day's End Mountains, the various lords of the high peaks rallied their hosts to war, joined by a legion of daemons sent from the Realms of Chaos to make an example. Taken together, the armies of Chaos massively outnumbered and out-classed Rebecca's troops. The battle against the sorcerers had been an uphill fight. This would be a slaughter, both for her partisans and for everyone living in the region.
She knew of only one solution- to enter the Gate, descend into the Tomb of Eternal Life, and seek the aid of the spirits there. There were funerary rites, known to the people of that land but never to the foreign followers of the Dark Gods, that Rebecca now underwent, preparing her soul for the passage. She cut her hair and donned a funeral shroud, darkened her eyes with ashes, stripped off her shoes and bid a tearful goodby to Abraham. Then she went before the Gate, alone.
To the amazement of everyone watching, it swung open, revealing the beginning of the Long Stair inside. Rebecca placed one foot in, then the other, then started down- but a few steps in, she looked back. The outside world was darkened, as though viewed through a veil of fog, and her heart clenched as she realized that this meant that she could never return to walk among the living.
Steeling herself, she continued downwards. For a day and a night she walked without ceasing through gloomy, damp caverns, her way lit only by a candle, alone except for the drip of water and the echo of her footsteps. Finally, even as her legs screamed out for rest, she reached the bottom of the Long Stairs- only to be greeted by the sounds of battle. To her amazement and horror, she saw that the armies of demons she meant to fight were already here, waging war against the souls of the dead. Already a quarter of the Tomb had fallen and been corrupted by the minions of the Dark Gods, and even now the ancestral spirits of warrior kings led their hosts in desperate battles to hold back the defiling tide just a little longer.
The spirits of the dead were perplexed by Rebecca's presence, seeing through her shroud to the mortal life that still flared within. She begged leave to plead her case before them, though, and after some consultation she was allowed to appear before the Synod of Fifteen, the council of the greatest souls in the Tomb. Here, she laid out the dangers facing her people, the crushing burden of Chaos, the slaughter that awaited them if no help came, the defiance they had cast in the teeth of the Dark Gods. To this, she added what she had learned from the ruins of the sorcerer's tombs- that a plot was afoot among the disciples of Tzeentch, to take the souls that fell in battle in the Tomb and weave them together into a monstrosity, an ur-eidolon of a million trapped spirits capable of shaking the walls of Heaven themselves.
The Synod was divided. Half were for marching out into the realms of the living and facing the enemy in battle, while half feared abandoning their homes and suspected a trick by the Dark Gods to undermine their defense. Only the ruler of them all, the ancient king Xereus, remained pensive. He said that since the Synod clearly could not come to a decision, perhaps it was time to present the choice to the entire population of the Tomb to see what their verdict would be. This proved to spark no less controversy, however. Some of the spirits took up arms and were ready to follow Rebecca up the Long Stairs and to battle, while others were ready to kill her as an agent of the Enemy then and there. Most, however, wavered somewhere in between, afraid of leaving their homes but equally afraid of remaining to be fodder.
Finally, a single voice broke the tumult. To Rebecca's surprise and grief, she saw Abraham standing before the masses. When he realized that he would be forever parted from his love, he said, he had thrown himself from a cliff- but now he would speak of her character, and in her defense. He told of how she had been the first to take up arms in defense of his people, how she had rallied them to her banner with her strength of will and courage, how she had cleverly lead the armies of Chaos to their doom, and how she now was prepared to sacrifice her own life to defend those around her.
At this, others in the audience who had died since the beginning of the tide of Chaos joined in, adding their voices to the call for action to defend the people of the mountains. Finally, the ancient guardians of the gate came forwards. They had long stood their watch to make sure that the worlds of life and death remained separate- but now that a greater threat had arisen, that time had passed. It was time for the living and the dead to be rejoined- time to pierce the veil at last.
At this, Xereus nodded. He would lend his support to the march on the surface, and together the living and the dead would liberate the world above from the grips of Chaos. But this, he said, would only happen on one condition- that Rebecca, who had lead the armies above, would shed her mortality and join the ranks of those below. With the love of her life dead, and her people facing destruction, the choice was not difficult. She assented, and at a stroke of his sword her living spirit was snuffed out.
Two days later, as the armies of the lords of Chaos stood poised to sweep over the region and slaughter its people, they were met with an army of spirits and an army of men, fighting in ranks together. The shattering defeat of the fell horde gave new heart to all who heard of it, and many in the lands around the Day's End mountains rose up against their once-invincible masters. Wherever these rebels arose, they were quickly joined by ghostly and living soldiers, fighting with fury and guile borne of decades or centuries of experience.
It took years, but the whole of the mountains were freed, and remained free in their mountaintop fastnesses even against the legions that the Dark Gods sent to cast them down. But irony of ironies, Rebecca was not at their head, nor even in their ranks. When she had fallen beneath Xereus' blade, her soul had been snatched up by Sigmar, to join the ranks of his armies.
Reforged, she was indignant, and then moody, prone to keep her own counsel and withdraw from the company of others, appearing alive only when she faced down the minions of the Dark Gods where she was terror itself. In his wisdom, Sigmar saw only one place to put her- the ranks of the Death Watch, full of misfits and outcasts and juggernauts like her. In Steelios, she found a companion that could ease her pain- someone who understood her anger at the gods, and abided by her refusal to swear allegiance to any. Now, she fights determinedly at his side against multitudes of foes across the Realms- but her mind wanders to Shyish, and the mountains of the Day's End, and the promise she made to King Xereus long before...
The storytellers call Rebecca the Beloved of Eternity, the Dusk Raider, the Denied, the Guardian of Death, the Nineteenth.