Disclaimer: This story contains spoilers for XCOM: Enemy Unknown and XCOM: Enemy Within. It also contains spoilers for Diablo III and may contain spoilers for The Reaper of Souls.

1.

Secrets of the Ages

A full moon had passed since the fall of the Prime Evil. An uneasy peace of sorts had settled upon the High Heavens since the Great Invasion of Hell. While the survivors had soldiered on, the way of life for the Seraphim had still changed irrevocably. Even as Tyrael, the Aspect of Wisdom, stood upon the bridge overlooking the Silver City, he could still see the scars of Diablo's rampage, the near-victory of Hell that would have come to pass if it not had been for the heroic efforts of the mortals known as the new Nephalem.

Despite the promise of a brighter future and an alliance between the Nephalem and the Seraphim however, all was not well in the High Heavens. Tyrael might have been appointed The Aspect of Wisdom by the leaders of Heaven, but he knew it was a role not many of the Seraphim could accept a mortal taking on. No, even if that mortal had previously been an angel, the Archangel of Justice himself, no less.

Tyrael frowned. He had no regrets on choosing to give up his Seraphim form to become a mortal. The actions of the Nephalem had proven his choice right, his sacrifice worthy. But still...

He broke out of his dark thoughts when saw the raven coming. The drab mortal creature, looking very out of place in its celestial surroundings, was laboriously making its way through the air, wings working hard to keep aloft. Tyrael knew the creature by sight; the raven had been a companion of one of the Nephalem who had defeated Diablo. Yes, the dour one with the penchant for incendiary explosions, the demon hunter who went by the name of Vrom. As the raven spotted him and purposefully changed course, he wondered what had brought the bird here. Then as it drew closer however, he noticed the heavy burden it carried— a bundle of scrolls, securely wrapped in oilskin.

"What message do you bring from Vrom, my feathered friend?" Tyrael greeted the messenger bird, offering a perch in the form of his shoulder. The weary bird gratefully accepted, and allowed Tyrael to remove its load. Not without some relief too, he imagined; the parcel was comically overlarge for a bird of its size. Vrom was every bit as wordy in his writing as he was with his speech in real life, which made for heavy dispatches, and the poor bird had really had to put in some effort to get its delivery to its intended destination.

Tyrael chuckled as he unrolled the bundle of scrolls, welcoming some news removed from the politics of Heaven and the Angiris Council. He was however, duly surprised when instead of Vrom's usual rambling epistles there was only a relatively short message in the bundle, and the rest of the delivery contained a collection of illustrations. Tyrael glanced at unusually terse note accompanying them:

Tyrael,

Some new malevolent force has been laying siege to our demon hunters in the Dreadlands. What troubles me is they do not resemble the remnants of the forces of hell after the Prime Evil's defeat, nor do they seem to have any purpose in attacking us that I can comprehend.

I have included a drawing of the creatures we glimpsed, including the one that was leading the invasion forces. It is quite accurate to how it looks in person. As you know I have a good eye and steady hand for such things. Another thing: I know the feel of demons well, but the power this creature had felt nothing like theirs. This one reminded me of the corrupted angels we encountered when Diablo invaded the Crystal Arch, but without the reek of demonic taint.

I do not know how to explain it or what it wants from us, but I intend to find out. I may also choose to find out by the means of filling its head with bolts.

One more thing: it made a mention of the Angiris Council. If you recognise any of these demons, or who this fallen angel is and why it should choose to command an army of demons against us, please send word by return raven. Corvus, my raven, will find me.

Your friend,

Vrom

PS: If this fallen angel is of any importance and if there is any reason why I should not fill his angelic head with bolts, also send word by return raven. You might wish to tell Corvus to make haste in that case.

With chagrined curiosity, Tyrael unrolled one of the parchments containing Vrom's illustrations. The first showed a strange, egg-headed imp-like creature, the second showed a strange aberration that looked like a gargoyle cut in half, and the third showed a prickly spider-creature with spear-like legs. Hideous monstrosities indeed, but nothing that seemed spectacular enough for a Nephalem who had faced the worst of the armies of hell to be worried about.

Then Tyrael picked up the last illustration and froze in recognition. The distinctive visage of an individual long forgotten jumped out at him through the rough but uncannily accurate lines of Vrom's drawing. The parchment crackled as Tyrael involuntarily clenched his fists. It was unmistakable, the shape of that headress-hood, the pattern of those robes... despite himself the former archangel-turned-mortal found himself blurting out a name none of the Angiris Council had uttered for eons, or ever wished to hear of again.

The beauty of the restored Gardens of Hope flashed by unheeded as Tyrael hurried his way to Library of Fate, startling the seraphim he encountered in his mad charge. He did not stop running until he arrived and burst through the doors.

"Itherael!" he managed to gasp out before having to stop for breath so he could continue speaking. There were drawbacks to being restricted to a mortal form. It was only then, when he was still catching his breath, when he became aware of the presence of Auriel, Archangel of Hope, in Itherael's sanctuary as well.

"What has happened, Tyrael?" she asked, looking at him with concern.

He returned her concerned look. Behind her, Itherael, the Archangel of Fate was in a state of great agitation, aimlessly circling with the Scroll of Fate firmly in his grasp. "All of creation bows before the New One, the tyrant overwhelming..." he recited feverishly. "It changes, every iteration darker than the one before it!"

"Tyrael?" Auriel prompted, drawing Tyrael's attention back to her. He quickly realised that he had interrupted her while she was trying to calm Itherael down but chose not to comment on it.

"I came to consult Fate, but it seems he too, has foresight of the ill tidings I bear." He showed Auriel the drawing Vrom had sent him. Just as he had, she recognised him immediately.

"Ubethrael...?"

"Yes," Tyrael said grimly. "He was seen near Arreat, which means that not only have The Ethereal Ones escaped their eternal prison in the Void, they have discovered Sanctuary as well... "

"...and the existence of the Nephalem," Auriel finished for him, her tone grave as she too, understood the implications.

Itherael, still agitated, finally ceased circling and floated back down to join them in discussion.

"If Ubethrael realises what the Nephalem are, and the extent of their potential power, he will no doubt seek them out for another attempt at Ascension."

Tyrael's face was grim as memories of the past surfaced. "We cannot allow Ubethrael to succeed. If he does, there will be nothing left in all creation that can withstand him, or the return of The Ethereal Ones."

End of Chapter 1