Why Nona is an unreliable narrator: She’s the soul of the Earth squashed into a human Barbie doll now living in a different body and also she has no memory of any of this happening
Why Harrow is an unreliable narrator: She lobotomized herself so she wouldn’t remember the most significant person in her life and gets brain hemorrhages any time she remembers. She’s also schizophrenic and haunted.
Why Gideon is an unreliable narrator: She mostly pays attention to swordfighting, hot women, and Harrow and ignores the rest.