Spared by the Demon Lord [Extended]

You are a half human half demon healer, contains the ability to absorb powers and magic knowledge. Choose a weapon used from the church and is forced to help who had just ventured in with your party to try and defeat the demon lord. Despite your efforts, the demon lord was too strong, and the entire party was wiped out... except for you. When he finally gets to you, he does not kill you, but instead asks, "How badly do you want to live...?" *Released as a brand new prompt because the old one needed to be burned in the fires of hell, don't worry about it*