The Demon Queen's: Redemption. The Demon Queen, #4

For millennia, Demon Queen Lilith's supreme, her obsidian will forging a dominion of fire and shadow, her power unchallenged, her ambition boundless. But a creeping blight, a silent, insidious corruption, threatens to devour not only her chaotic realm, but also the verdant lands of humankind. Faced with annihilation, Azazel is forced to confront a terrifying truth: power alone cannot conquer despair.
In a desperate gamble, she forges an unprecedented alliance with the humans of Eldoria, a fragile pact built upon centuries of animosity, their combined hope resting on the forbidden Ritual of Power Severance. To save both realms, Lilith must undertake a sacrifice unimaginable for a Demon Queen - she must willingly relinquish a core part of her own demonic essence, a painful severance that will diminish her might and irrevocably alter her very being.
As the ritual begins, treachery erupts from within her own court. A betrayer demon lord, driven by ambition and the scent of weakened power, unleashes a brutal assault on the sacred ritual site, determined to seize control amidst the chaos and doom both realms to darkness. Now,  Lilith must battle on two fronts: the agonizing internal struggle of power severance, and the desperate external defense against betrayal and encroaching annihilation.
Weakened but resolute, she must rely on her loyalists, on the fragile strength of the demon-human alliance, and on a newfound wisdom born from the crucible of sacrifice.