Diablo 4 draws on the plot of the entire series so far. With the original Diablo having been released over 25 years ago, there is a wealth of detailed storylines to catch up on for newcomers to the series. This includes three mainline games, four expansions, a mobile MMOG, and 15 novels that weave even more detail into the game series’ world.
But the story of Diablo 4 looks like it primarily draws on events that predate the first Diablo; a never-ending war known as The Great Conflict. While this fight hasn’t directly factored into the mainline games, it is an incredibly important part of Diablo’s history that establishes the hidden power of humans. The Nephalem protagonist from Diablo 3 conquered angels and demons alike, proving how powerful humans truly are. This might of humanity against Heaven and Hell has blossomed in blood, building across every Diablo game so far.
The Original Diablo - Humanity Butchered By Demons
The first Diablo begins in Tristram, a town ruled by King Leoric that unknowingly harbors The Lord of Terror himself deep beneath its cathedral. Long ago, an ancient order of human mages known as the Horadrim trapped Diablo inside a special gem known as a soulstone and buried him underground. Slowly, he shook free of his shackles and corrupted the minds of the townsfolk above. Tempted by Diablo's call, Archbishop Lazarus shatters the soulstone and releases Diablo. From here, Diablo turns King Leoric mad and possesses his younger son, Albrecht. Lazarus leads the villagers to slaughter, and despair spreads.
Aidan, King Leoric’s eldest son, returns from war to restore peace to Tristram. With the wisdom of Deckard Cain, the last Horadrim, and a witch named Adria, Aidan learns of Diablo’s evil influence and ventures beneath the cathedral to confront him. Along the way, Aidan kills his father King Leoric - now the Skeleton King - and Archbishop Lazarus. In Hell, Aidan finds that Diablo’s soulstone has been embedded in Albrecht’s forehead to control him. Despite this, Aidan fights Diablo and returns him to the soulstone. So that this terror may never escape again, Aidan plunges the soulstone into his forehead and resolves to keep Diablo suppressed.
Diablo 2 - The Three Prime Evils Corrupt Humanity
Unsurprisingly, Aidan’s plan to suppress Diablo fails: he goes mad and travels the world wreaking havoc as a figure called the Dark Wanderer. A new unnamed hero emerges (depending on the Diablo 2 class chosen) and resolves to put an end to the Dark Wanderer. It soon becomes clear that the Dark Wanderer is possessed by Diablo, and he aims to release his brothers Baal and Mephisto. These three are known as the Prime Evils, demons who led an ancient religion known as the Triune. The Dark Wanderer forces a mage known as Marius to undo the seals on his brothers, unleashing the Triune on the world.
Thankfully, the hero is guided by the angel Tyrael who originally formed the Horadrim. With Tyrael’s help, the hero tracks Diablo, Baal, and Mephisto to their hell portal. The hero is forced to fight Mephisto, trapping him again, before venturing deep into hell and confronting Diablo. Even Diablo falls before the hero’s might, captured once more in the soulstone. So that they might be forever defeated, the hero takes their soulstones to the Hell Forge and shatters them. Baal eludes capture, however, plotting to one day take back his own soulstone and destroy it, so he can never be sealed away again.
Diablo: Lord Of Destruction - The Worldstone Destroyed
Baal tricks Marius into giving him the soulstone by disguising himself as Tyrael. He kills Marius and sets to work on his new plan: corrupting the Worldstone. The Worldstone is an ancient artifact that allows the existence of Sanctuary, the realm between Heaven and Hell. If Baal corrupts the Worldstone, all humans will fall under his command. This is crucial, as humans are, in actuality, a powerful race of half-angel half-demon offspring known as Nephalem. Baal is ultimately defeated by the hero, but not before corrupting the Worldstone. To prevent humanity’s downfall, Tyrael shatters the Worldstone - the consequences of which won’t be seen for many years.
Diablo 3 - Maternal Betrayal And Demonic Resurrection
Twenty years after the Worldstone’s destruction, Deckard Cain predicts the next hellish invasion while raising his adopted daughter Leah. This war comes to him when a Stranger falls from the sky, crashing through his cathedral. The dead rise from their graves and a new hero (this time depending on which Diablo 3 class and abilities the player chooses) arrives to put the dead to rest. The hero restores the Stranger’s memory: he is Tyrael, but he voluntarily shed his angelhood to become a Nephalem and protect Sanctuary. Sadly, this knowledge comes at a cost: Cain is killed by a follower of Belial, one of the Lesser Evils.
To avenge Cain and put evil to rest once and for all, the hero sets out to defeat the last living Demon Lords: Belial and Azmodan. On their journey, they find the witch Adria from the events of the original Diablo: it turns out she is Leah’s mother, who entrusted Leah to Cain while she ventured out to defeat Belial and Azmodan. With her help, the Hero captures Belial and Azmodan inside the Black Soulstone, a relic that can contain the essence of all seven Demon Lords. If this is destroyed, evil will be vanquished forever.
But Adria has no intention of doing so: she secretly pledged her fealty to Diablo back when he controlled Aidan. Together they had an offspring: Leah. Leah as Diablo’s daughter is the perfect host for the Demon Lords. Adria implants Diablo into Leah, and he is reborn, powerful enough to invade Heaven and defeat the Archangels that protect it (known as the Angiris Council). Determined to persevere, the hero helps the Archangels to close the hell rifts before finally confronting Diablo. The hero unleashes their Nephalem might and plunges Diablo into the void. With this victory and Tyrael’s ascension to the Angiris council, the angels finally unite with humanity.
Diablo 3: Reaper Of Souls - Rise Of The Nephalem
Tyrael takes the Black Soulstone and seals it away in Sanctuary, but he is interrupted by a defector from the Angiris Council: Malthael. Malthael left Heaven when the Worldstone was destroyed and watched as the Nephalem proved themselves to be stronger than both angels and demons. To eradicate all demonkind, Malthael resolved to kill the Nephalem too. To this end, Malthael steals the Black Soulstone and tweaks it to capture all demonic essence including that of the Nephalem. In effect, he would destroy humanity. The hero kills Malthael to prevent this, but in doing so only proves Malthael’s point: all Nephalem are a ticking time bomb.
Diablo 4 - The Tainted Love Behind The Nephalem’s Origins
This Nephalem plot traces back to early in Diablo’s world. Since the beginning of time, Heaven and Hell have been locked in an eternal battle known as The Great Conflict. During this time, an advisor to the Angiris Council known as Inarius sees that this fighting will never end, and seeks out angels and demons who want to create a world away from the war. Eventually, he finds Lilith, the daughter of Mephisto, and together they steal the Worldstone so that they can create Sanctuary. Their alliance is not simply tactical however; they soon fall in love and their forbidden union forms the first of the Nephalem.
The Nephalem are incredibly powerful due to their angel and demon heritage, and so both Heaven and Hell must agree on how to control them. Inarius is indecisive, but leans towards killing them. Lilith opposes this, thinking the Nephalem have the power to end The Great Conflict. When Lilith finds out her children are being killed, she seeks vengeance by slaughtering her fellow renegades in Sanctuary. Inarius has no choice but to banish her to the Void, ending their love once and for all. The Worldstone is later tuned to make the Nephalem forget about their great power - and so, humans are created.
This is the hidden truth that Diablo 4 looks set to unearth. In the trailers, Inarius raises his followers, the Pale Knights of the Cathedral of Light, and charges into battle against his former lover Lilith. One key character remains as yet unidentified however: the sorcerer that brings Lilith back from the Void with the blood of three men - setting a more sinister direction for Diablo 4. This sorcerer may manipulate Lilith to revive the defeated Demon Lords, including Diablo. This would allow for the requisite final fight with Diablo, a staple of the series that is almost certain to recur in Diablo 4.
