All three main characters of Lizard State are intentionally hiding their personality and trying to reinvent themselves. Max acts like a clown, but he's lonely and much more aware of himself than he seems. He ends the story seeming about the same, but much more able to handle and express negative emotions than his human self. Vi made herself tough to survive her childhood, and is trying to find herself under all that. Ironically, she becomes more similar and more empathetic to her human self by the end. Nano is more complicated.
Nano has already redefined themself after rejecting most of their personality and their past, good and bad. Reappearing after a long absence, they're prepared to make the most of a new opportunity. In the end, Nano reconnects with their community, but must first resolve issues caused by their disappearance, both literal and the loss of who they used to be.
Nano is a daredevil with a big ego, regularly getting themself and their partner Sed into danger while exploring. Their motive for exploring is selfish. Exploring makes their life eventful, ranging from investigating small disturbances to mapping out unpopulated lands. They are prideful in their work, especially when they get to share their experiences. Storytelling is highly valued in their culture, from oral tradition to autobiographical accounts (to gossip). This makes Nano and Sed local celebrities. Sed partly enables Nano's dangerous behavior by taking care of fights. Sed is much more benevolent, dedicating themself to helping others in need. (Nano is on board mostly for the fame it gets them.) The two meet many such travelers while exploring, but Sed follows Nano since they're regularly in danger.
In a fight with an unknown monster, Nano escapes early at Sed's order, then Sed makes it out alive but in critical condition. The two travel to a gathering, and Sed recovers with some disabilities. After reevaulating themself, Nano publicly leaves alone, despite it being taboo. They isolate themselves to become a "better" person. They resolve to be more like Sed, but its pointless without anyone around to help. Even so, they avoid all news about them.
All this happens before the story starts, with Nano finding Max in similarly critical condition and leading him to a gathering. Max knows them as an infinitely knowledgable mentor. Vi knows them as a veteran somehow more jaded than she is. Both are aware Nano is hiding something, and they don't (intentonally) pry. However, an entire community knows the old Nano. They're sympathetic and accepting, willing to ignore the change. Some are less so, having been affected by Nano's actions or absence.
