Angel Sacrificed to the Abyssal Demon

Isabella was the pureblood angel they all used. Her mother was killed. Her father didn't care. Her stepsister took everything. When the Abyss demanded a sacrifice, Isabella volunteered—not for glory, but for her sister. She bound herself to Azriel, the fallen angel the world fears. But the man she loved, the archangel Sebastian, had only been using her to protect her stepsister. After humiliation, betrayal, and a fall she barely survived, Isabella walked into the Abyss. She thought she was walking into death. Instead, she found a wounded fallen angel who needed her light. Can she heal the demon everyone fears?