"God... destroy all these deities!"
The green flames were not her own power; being able to use them was a miraculous theological reaction occurring from the combined divine powers, particularly the discarded divine power and Victory's divine power playing the most significant roles... Failure meant great success, and damage meant continued usage.
Moreover, her account character was created by the Goddess of Disorder, inherently having a strong connection with the goddess herself. With the goddess's physical form becoming increasingly pathetic, her, as an information projection and player's avatar, naturally gained high-level access to use the Green Flame, and a portion of the Green Flame had already firmly attached itself to her.