The god of fate is already fighting the god of death and the god of disaster. If the god of luck decides to join the fight against her, she will lose. But that is exactly what she wants to happen right now.
She made up her mind to force the god of luck to take more actions against her. That way, she will be able to predict him better and plan for his actions in her future endeavors.
Her mind was made up about this when the god of luck refused to talk to her. His silence made it obvious that he was afraid of her.
Now that she was willing to fight the god of death, the god of luck would have to show up to stop her or watch her be victorious in her fight and kill the god of disaster.
In order to force the hand of the god of luck, she used her ultimate ability together with her rank 2 Curse divine ability. She wrote in her Book of Fate with the power of a curse that the god of death will die at the hands of the god of life.
