Inheritor: Extra In My Own Novel

In the world where gods are all fallen, the world which faces crises of other worlds and threats of monsters.

in between the infight amongst the humans who are at the same time fighting against the whole world, follow the journey of Lucifer Mors who travelled into his own novel which was based on his own messy life as himself an extra in the novel and protagonist as his half-brother who is his biggest enemy.