Players take on the role of heroes as they slay demons that threaten the world of Sanctuary in Blizzard's acclaimed Diablo franchise. Players have taken on the role of Barbarians, Sorcereresses, Paladins, and even Amazons against the forces of the Burning Hells in the Eternal Conflict. Canonically, the player's main character in the first game will become Diablo's vessel in Diablo 2. Meanwhile, D2's main characters become famed adventurers that had varying fates throughout the years.
Diablo 3 in particular adds more weight to the player's status as heroes. In D3, players become the Nephalem - half-angel and half-demon spawns that trace their origins to the beginning of Sanctuary. However, despite the grandiose nature of their identity, the Nephalem seem to have critical importance in the upcoming Diablo 4. Blizzard teased the return of Lilith, Daughter of Hatred, and mother of the first Nephalem. Just what other things should players remember about the Nephalem?
10 Nephalem Aren't Angels Or Demons
When Inarius and Lilith created Sanctuary from the Worldstone, they finally had a realm away from the Eternal Conflict. However, what the couple and their renegade angels and demons didn't expect was the prospect of procreating. They would be soon called the Nephalem.
Thanks to the nature of the Nephalem, they possess powers of both their angel and demon parents. However, their unique nature made them separate - and perhaps "more" - than what their parents could have been. It's prophesized that the Nephalem could hold power more powerful than angels and demons, explaining the powers of humans throughout the Diablo series.
9 Lilith And Inarius Bore The First Nephalem
Of all the Nephalem, it's Rathma that had come into Sanctuary first. Born Linarian, Rathma was the offspring of Lilith and Inarius, effectively heralding the arrival of Nephalem in the universe. It was Linarian who realized that Light and Darkness will eternally clash. Linarian got the motivation to study the cycle of life and death, eventually earning the interest of Trag'Oul.
Unlike Anu of the High Heavens or Tathamet of the Burning Hells, Trag'Oul represents the Great Balance. For Trag'Oul, there has to be enough good and evil for the world to remain intact. In his time with Trag'Oul, Linarian will name itself Rathma. It's Rathma who will found the Priests of Rathma, who will eventually become today's Necromancers.
8 The Ancients Were The First Nephalem
Alongside Rathma, more beings will comprise the first generation of the Nephalem, known today as The Ancients. They will come to forge and create vastly-different cultures that will eventually make up the diverse landscape of Sanctuary's geography today. The Ancients will also become the first members of organizations of classes players use in the games.
For instance, Bul-Kathos the Immortal King, and Vasily decided that it's the Nephalem's sacred duty to guard Mt. Arreat and the Worldstone. They each created the first generations of Barbarians and Druids, tackling the task in their own way. Meanwhile, Esu's mastery over the elements led to the creation of the Zann Esu Clan of Sorceresses.
7 Nephalem Could End The Eternal Conflict
When Lilith and Inarius used the Worldstone to create Sanctuary, the Archangel remained content in their escape into a realm to call their own. However, Lilith craved for an ending to the Eternal Conflict she was forced into participating. Lilith found her potential salvation in the form of the Nephalem, the offspring between angels and demons.
Unfortunately, both angels and demons feared the potential inside the Nephalem, as their children may soon develop the power to surpass their forefathers. However, whereas their fellow rebels wanted the destruction of the Nephalem, Lilith wanted to manipulate the Nephalem into becoming her weapons.
6 Nephalem Had Sealed Potential
The Nephalem encountered numerous occasions of losing access to their innate potential. For instance, Inarius banished Lilith when the latter went on an outburst and killed their fellow renegade demons and angels. Her outrage happened when she heard they clamored for the Nephalem's destruction. Thankfully, Inarius decided to keep the Nephalem alive. However, he also manipulated the Worldstone into making each generation of Nephalem weaker than the last.
Additionally, Uldyssian of the Edyrem also sacrificed his Nephalem powers to stop the war between the Edyrem, the Burning Hells, and the High Heavens. Sadly, his sacrifice also sealed away all of the Nephalem's powers.
5 The Sin War Created Systems Of Control
After Inarius sealed the Nephalem's powers away, his offspring began forming cultures of their own. Unfortunately, the Spirit Clan's desire to commune with spirits instead opened communications with demons. It's the Burning Hells that first discovered Sanctuary's existence. However, knowing Inarius had been guarding them, demons led by Lucion formed the Triune - a cult based on the worship of the Prime Evils, disguised as benevolent deities.
Meanwhile, Inarius caught wind of these schemes and created the Cathedral Of Light, based on the High Heavens' teachings. Lilith, who found a way back to Sanctuary, wanted to reawaken the Nephalem's potential to serve as her soldiers. This complex interplay of religious politics became the Sin War - a proof that the High Heavens and Burning Hells both wanted to control the Nephalem.
4 Uldyssian And The Edyrem
Inarius' sealing of the Nephalem's powers didn't stop them from rediscovering their potential. One such being came in the form of Uldyssian ul-Diomed, an ordinary human Lilith (as Lylia) manipulated to create a third faction in the Sin War. Initially, Lilith used magic to fake magical feats Uldyssian performs, unbeknownst to his knowledge. However, Uldyssian's true powers reawoken after he confronted Lilith about this deception.
Uldyssian's reactivation of his Nephalem powers also "activated" the latent abilities of his powers. Now called Edyrem, they sought to destroy both the Triune and the Cathedral of Light for their attempts of controlling them.
3 Nephalem Were Almost Destroyed
When Rathma tried to intervene in the Sin War, his actions caught the attention of the High Heavens. The High Heavens saw the potential of the Nephalem to be a force of destruction. Realizing that his awakening of the Edyrem may have doomed them, Uldyssian formed the ultimate sacrifice of erasing his own existence. Unfortunately, this action also deactivated the powers of the Edyrem and all potential Nephalem.
However, thanks to Uldyssian's sacrifice, the High Heavens voted against the destruction of the Nephalem. With Uldyssian as an example, the Archangels realized that the Nephalem can follow both the path of good or evil with their actions.
2 Humankind Reawakened The Nephalem
Given that the Nephalem slowly lost their powers over time, their "depowered" selves have become Humankind in Sanctuary. The High Heavens and the Burning Hells used to leave Sanctuary to their own devices, with secret agents "influencing" them through small actions. Unfortunately, both sides had to act directly given more widespread actions towards Sanctuary. For instance, Baal and his monstrous minions's corruption of the Worldstone forced Tyrael to destroy. However, this also left Sanctuary exposed once again to the Burning Hells and the High Heavens.
It seems the destruction of the Worldstone "resetted" the original status of Humankind as Nephalem, beings of powers greater than demons and angels. This may explain why the Nephalem once again walked Sanctuary just in time to destroy Diablo, who had become the Prime Evil, and end the Great Conflict.
1 Nephalem Were Beyond Destiny's Reach
The Chalad'ar or the Chalice of Wisdom serves as a vessel of infinite light that showed its wielder the destiny of all things in existence. Malthael the Aspect of Wisdom used the Chalad'ar to know the fates of everything in existence. Unfortunately, Malthael discovered that the Nephalem were beyond the reach of the Chalad'ar. Worse, the Burning Hells can find ways to control the Nephalem and defeat the High Heavens.
Malthael's fall into the Angel of Death predicated upon his desire to rid humans of their demonic essences. For him, killing the humans this way will at least secure the victory of the High Heavens. His realization also meant that for as long as humankind intervenes in the Eternal Conflict, they can become a vehicle of peace.