Worldstone

"The Worldstone. It was the power of creation and the birth of our Eternal Conflict. From the High Heavens to the Burning Hells, our desire to control that power poisoned its very nature. And so... I gave my life to destroy it."

- Tyrael

The Worldstone, otherwise known as the "Eye of Anu," "Heart of Creation," and "Heart of the World" was a colossal, mountain-sized object of immense power. Sought by both angels and demons, it would be used to create Sanctuary before being destroyed as a result of the Great Conflict. And yet for all its importance, few of Sanctuary's inhabitants are aware that it even existed.

Lore
"By Rathma...An endless sea of souls have perished because of this stone. It is a beacon to life and death."

- A Necromancer

The Worldstone had the power to shape entire realities. It could not be cloven through any means other than the weapon of an archangel.

One could not teleport straight up to the Worldstone&mdash;there was apparently a proximity where the process became too dangerous.

Even fragments of the Worldstone possess immense power. Examples include the soulstones, the Fragment of Destiny and according to the beliefs of some, Blood Shards.

Early History
The Eye of Anu originally lay in the realm of Pandemonium, the scar of the universe's violent birth from the battle between Anu and Tathamet. It was the foundation of all places and times, a nexus of realities. When the angels were young, Malthael was the one who discovered the Eye, and named it the Worldstone, and swore all of Heaven to protect it.

Both Heaven and Hell sought control over the Worldstone. Oral history states that whichever side controlled the stone allowed it to alter reality and create life and worlds with barely any restriction. Both angels and demons created worlds that reflected their nature, but all of these worlds were inherently flawed, and were doomed to wither and die. At some point, the archangel Tyrael ordered that a bastion be built around the stone, which would come to be known as the Pandemonium Fortress. The fortress changed hands many times over the course of the Great Conflict, and the possession of the Worldstone alternated in turn. As the conflict dragged on, the Worldstone became 'poisoned' by Heaven and Hell according to Tyrael, due to their desire to control its power, altering its original nature.

Sanctuary and the Sin War
"It is the reason why no nephalem or anything akin to it has risen lo these many centuries, my friend. It is the reason why you and yours should not exist! You stand before the curse of all of all the descendants of those angels and demons who forged Sanctuary! You stand before the Worldstone..."

- Rathma to Uldyssian ul-Diomed

Over the course of the Great Conflict, a number of angels and demons had grown tired of the endless war and desired a place away from the conflict. These renegades were led by the angel Inarius and the demon Lilith. Either through strength of arms or misdirection, Inarius and his renegades gained access to the Worldstone. Altering its frequency or dimensional alignment, they used its power to conceal it from the angels and demons still fighting in the Eternal Conflict. Subsequently, the Worldstone was shifted into a pocket dimension. There, Inarius and his followers shaped a world around it. A world of refuge they would call Sanctuary. The forces of Heaven and Hell became aware of the Worldstone's disappearance, but had no idea where it was or who had taken it. Either way, far removed from the squabbles of his former allies and enemies, Inarius shaped Mount Arreat as a kind of protective shell around the Worldstone. From there, the rest of the world would be formed.

The Worldstone could be used to alter the abilities of certain individuals. Unknown to the renegades, Inarius tied the energies of the Worldstone into himself, enhancing his powers greatly. The Worldstone was further used to inhibit the powers of the nephalem&mdash;the offspring of both angels and demons and with the potential to become greater than both. Over time, as each generation of nephalem became weaker than their predecessors, the race that would be called humanity arose. However, the potential for Man to reclaim his former strength still existed, and during the last days of the Sin War, it was potential that began to be reclaimed. Lilith, having long since fallen out with Inarius, cast a spell on the Worldstone that would allow humanity's former power to return.

Events began to get out of hand, however. Uldyssian, the first to reclaim his nephalem birthright, came into contact with the Worldstone, changing the pattern of a small part of the artifact from five-sided to six-sided, thus changing its resonance. Unlike Lilith, he had changed the nature of the Worldstone itself, and the nephalem's powers began to return at an even faster rate. And Inarius could not undo the effects that Uldyssian's contact had wrought.

Uldyssian ultimately defeated Inarius and severed his connection with the Worldstone, but lost his own life as well. At the end of the Sin War, the Angiris Council and Mephisto agreed that Sanctuary and its inhabitants would be allowed continued existence, though one of the conditions was that humanity be taken 'back to the beginning.' This meant a second loss of their nephalem abilities, per another alteration of the Worldstone.

Worldstone's End
"And now at last the storm surges forth from the southlands, and the hand of Destruction reaches out to undo the workings of the Ancients. The tides of Hell surge&mdash;ready to smash down upon the shores of the mortal world&mdash;to drown the guilty and the innocent alike."

- Excerpt from The Prophecies of the Final Day

It is stated that when the world was young, the people of the Northern Steppes were given a sacred charge of protecting that which lay in the heart of Mount Arreat. These people were called Children of Bul-Kathos, a moniker that encompassed two distinct groups&mdash; the Barbarians, who remained in the steppes, and the Druids, who developed their own culture in Scosglen but vowed to return to the steppes at Uileloscadh Mor, the final battle between Heaven and Hell. For the Barbarians, the protection of the Worldstone was the cornerstone of their culture. Consequently, the Barbarians were quick to thwart any incursions into their lands and developed a reputation for savagery in the kingdoms to the south.

Eventually, the moment came. Baal, Lord of Destruction, approached Mount Arreat at the head of a demonic army. His plan was to infuse his soulstone shard with the Worldstone that had spawned it. His shard pulsated with energies of destruction, and, if fused with the Worldstone, humanity would fall prey to the powers of destruction as well. The Barbarians fought to stem the tide, but were driven back to the slopes of Arreat and their last bastion of Harrogath. Baal's forces laid siege to the fortress while thanks to the treachery of Nihlathak, Baal was able to claim the Relic of the Ancients, allowing him passage up the slopes of the mountain.

Ultimately, Baal was defeated by a group of heroes that had previously defeated his brothers, Diablo and Mephisto. However, they were too late to prevent him from enacting his plan. Tyrael, coming to aid the heroes one last time, determined that the only recourse available was to destroy the Worldstone. After opening a portal for them, the angel hurtled El'druin into the stone, shattering it.

Legacy of Destruction
"A shard of the Worldstone... we swore to defend it, and paid the price in blood."

- A Barbarian

The destruction of the Worldstone had grave consequences. Baal's body and his demonic forces were destroyed, but the surrounding area was devastated. Mount Arreat was left a smouldering crater, and even 20 years later toxic clouds of ash and arcane dust hung over the surrounding area. What was once the Northern Steppes became known as the Dreadlands and the demonic corruption ran rampant, altering both man and beast. The Barbarians were left scattered. The heart of their culture had been destroyed, and many tribes fell into a state of regression. With the destruction of the Worldstone, the very essence of Sanctuary and every person in the world began to change.

The Worldstone's destruction also held grave implications for Sanctuary as a whole. Sanctuary was no longer hidden from the sight of Heaven and Hell, and both angels and demons stared intently at the mortal realm. Furthermore, its dampening effect had prevented armies of demons and angels manifesting en masse, but with that protection gone Sanctuary was open to invasion

While the Worldstone itself was destroyed, multiple shards were scattered across the world by the blast that followed its destruction. The shards carried its corruption with them across Sanctuary; wherever they landed, corruption and death followed. The power of the shards varied, some imbued with the power of Creation, others with the ability to warp reality itself.

Ancient evils emerged, looking to take control of the shards to use them to enslave humanity. One such evil was Skarn, who sought to use the shards to resurrect Diablo, and reignite the Eternal Conflict. If he could obtain just one shard of the Worldstone, he would be able to remove humanity's angelic essence, leaving only their demonic side.

The Coven also took advantage of the chaos, spreading corruption wherever they trod. Deckard Cain, who'd conducted a Horadric ritual to ascertain the location of the shards, sought to destroy them. He enlisted the aid of a hero/group of heroes in this endeavor. The Wortham shard came into the hands of Eskara, who attempted to summon Skarn into Sanctuary, but was thwarted by the hero(es) and the shard retrieved. Cain informed them of the existence of the Ashwold shard.

The Ashwold shard came into the possession of Lethes a rogue Necromancer. She was confronted by the hero(es), and despite using the shard to bolster her own power, she was slain, and the shard taken into their possession. The hero(es) returned to Cain in Westmarch, who had no means of destroying the artifact, but told them of the Dark Wood shard, which had come into the possession of the Countess, which she wore around her neck. After the Countess was slain, her Worldstone shard was likewise retrieved.

The hero(es) returned to Deckard Cain in Westmarch, where he attempted to conduct a Horadric ritual to destroy them. However, the shards pulsed with corrupting energies (a result of Baal's corruption of the Worldstone five years prior), and the shards not only resisted their destruction, but spawned demons as well. While the demons were destroyed, Baal's corruption had apparently made it impossible to destroy the shards.

Recent Events
Twenty years after its destruction, the Worldstone's absence allowed Azmodan, the Lord of Sin, to summon his army onto the mortal plane in the year 1285 leading them against Bastion's Keep. Yet this was thwarted by the Nephalem, for without the Worldstone's dampening influence, humanity's inherent power was able to return in at least a select few.

Months later, angels were also able to manifest in force under the direction of Malthael, though they too were defeated.

Diablo II
The Worldstone appears in the last part of Diablo II: Lord of Destruction, however, it is never interacted with directly.

Quotes
Malah
 * "If Tyrael says the Worldstone must be destroyed, then it must. We cannot let Baal's corruption prevail! The world will change, true -- but who is to say it isn't for the better?"

QualKehk
 * "The destruction of the Worldstone does not bode well for our world. But I'll try not to worry… After all, we have warriors like you fighting for us and for the Light. Farewell!"

Deckard Cain
 * "So… The Worldstone was corrupted by Baal. And now Tyrael must destroy it. Worry not. Through whatever lies ahead I have faith that the Light will guide us both.

Anya
 * "Strange that you say that the Worldstone must be destroyed. The prophecies said nothing about that. Perhaps all we have fought for will be lost… or perhaps we'll never need fight again!"

Diablo Immortal
Worldstone shards are collected across the storyline of Diablo Immortal. However, they have no direct influence in-game.

Trivia

 * In 2014, it was unknown (in a real-world sense) what happened to the pieces of the Worldstone after it shattered. According to Valerie Watrous, it would be an "interesting" idea to explore this plot point in the future.  This idea became the basis of the plot in Diablo Immortal.


 * A Worldstone Shard was temporarily available as an artifact in Heroes of the Storm.


 * The Worldstone shards have been likened to "free uranium," in regards to their accessibility and power.