Creating Sanctuary and the Nephalim
The duo quickly gained a following of like minded demons and angels who had grown tired of endless war. Eventually Diablo IV Gold, the rebel group gained control of the Worldstone inside of the Pandemonium Fortress and used it to hide if from the sight of the Eternal Conflict. Inarius used the power to create a new world called Sanctuary, free from the ravages of war. The Worldstone was placed inside of Mount Arreat and the power of the artifact was secretly tied directly to Inarius who made himself the strongest being in Sanctuary and its ruler.
With a new world created and both angels and demons now co-existing, Lilith and Inarius had offspring called the nephalem. Containing aspects of both good and evil, these nephalem held power that was much greater than the angels and demons currently living in Sanctuary. Fear and dissension quickly broke out as some were concerned that the greatest sin was the fact that offspring created by an angel and demon would cause the Angiris Council and Prime Evils to take notice.
Pressure was put on Inarius to wipe them out, though he was unable to destroy his own children. Instead, Inarius re-tuned the Worldstone to cause nephalim powers to diminish over time and that any use of powers in his world would be punished. Lilith began turning on her followers over the prospect of her children being killed off.
Where are they now?
Following the carnage brought on by Lilith, Inarius captured and ultimately banished her into an endless realm called the Void, unable to kill her himself. While she eventually escaped during the Sin War, she was eventually defeated and sent back buy Diablo 4 Gold. She remained stuck in the Void for thousands of years until she was eventually summoned back into Sanctuary by a member of the Triune, followers of the Prime Evils.