Everything you need to understand or teach Black Bird, Blue Road by Sofiya Pasternack.
Black Bird, Blue Road is a middle-grade fantasy novel following 12-year-old Ziva on a quest to cure her twin brother, Pesah of his leprosy. When he is given less than a month to live, the two flee, accidentally freeing the half-demon Almas. He tells them about the city of Luz where Pesah can be cured, but only if they escape from the Angel of Death. This novel explores themes of grief, fairness, and death.