Chapter 687: Broken balance.
Lilith realized she was fighting Diablo in a barrier, but she didn't care; as long as she killed and tortured Diablo, nothing else mattered.
She stopped holding back long ago as she threw her destructive attacks at Diablo, causing massive damage to the former Demon King.
As a Demon Goddess, and a Progenitor, she was strong, incredibly strong, and when she used her True Form, that level of Power increased even further.
Long Demonic wings, sharp horns, and a tail covered in Miasma, a Miasma that began to spread throughout her body, a dense and corrupt Miasma; this was Lilith's current appearance.
As a Goddess, she could use Divinity, specifically the Concepts of Rottenness, Corruption, Despair, and of course, the Concept that led to her being called the Mother of Demons.
The reason she was a Goddess of Demons, specifically the Concept of 'Beginning'.