The World Is Collapsing, the Succubus and I Are Having Pure Love?

A world in which a brave man plays evil, and a succubus slave and a succubus come to save it? Recently, a reader asked about the settings. Could you tell me a little bit about them: 1. The world where the succubus lives is another planet 2. The world where the succubus was born has been destroyed by the brave. 3. Succubi can be immortal as long as they have "emotional desires". Immortality means immortality, and immortality means that they can be resurrected after death. 4. In addition, the heroine Succubus has true and pure love. Why? Will explain later