>>3206494They're one character and they have a single character's arc. Rei becomes convinced she isn't a person and lives for the next several years with that apparent disregard for herself, she's briefly allowed to believe that she could be a person and wants to try, that blows up and she's confronted again that she never was or could have been, she starts seriously considering what she could really be. The numbering is just easy delineation for her landmark experiences.