Unlike Inarius who settled to their escape in the Conflict, Lilith wanted to do more with her liberty. Thanks to this Worldstone's power, Lilith knew she could possess the power to Diablo IV Gold end the Eternal Conflict and eventually become the winning side. All she needed to do was convince Inarius of the same.
At some point in time, Lilith and Inarius sired a kid together, known as Linarian. No one anticipated that a union between their species was even possible. Linarian, that will eventually call himself Rathma, became the first of several Nephalem: half-angel, and half-demon hybrids. Unfortunately, many demons and angels would observe the untapped potential within the Nephalem that, if used incorrectly, could mean their destruction.
Subsequently, multiple demons and angels saw the Nephalem as threats. However, Lilith saw the Nephalem as her secret to winning the Eternal Conflict. Thankfully, Inarius chose to"meditate" on the matter of this Nephalem's extermination. However, Lilith became furious at the idea of killing her kids. She changed into a dreadful form and killed all of Inarius' followers.
The lore clarifies the Void as an"empty" realm that buy Diablo Immortal Gold can imprison various beings -- endless darkness. Rathma once clarified banishment to the Void for a fate"worse than death."