She is the wife of God Himself.
God and Nyx were the two primordial embodiments that created themselves before time itself began. Falling in love with each other, they collectively created the multiverse. Following the birth of creation, they created angels. It is unknown whether all angels where created at once, or one by one.
While her husband God is life and light, she represents darkness and death. She is one of the two fundamental components of reality itself, the other one is her husband, God.
Powers and Abilities
Extreme High-Tier Nigh-Omnipotence: As a primordial embodiment, Nyx can do just about anything she desires. In fact, collectively with God, she helped created the multiverse. Because of her nearly unlimited power, she is, along with God, the most powerful being in all of space and time. Even so, just like her husband, she is not fully omnipotent, because she's is his equal in both power and knowledge combined. In fact, while her husband God represents life and light, she represents darkness and death. She is also one of the two fundamental components of reality itself, the other one is her husband, God Himself.
Darkness Embodiment: Nyx is the physical manifestation as well as the personification of darkness, the all-encompassing void which acts as the counterbalance to light. The darkness manifested is essentially made of pure negativity as well as from the lack of illumination. Nyx can also essentially tap into the core of different forms of darkness itself to assert her dominion.