The Story of Zac
Zac began as a puddle. More specifically: he began as the result of a chemtech spill in one of Zaun's alchemical waste seams, where experimental compounds mixed with organic material and pooled in an unlikely confluence that, against all probability, became conscious. The two Zaunite workers who discovered the pool — Maline and Zaun, a married couple — did what their neighborhood instincts told them: they took him home and raised him.
Growing up as the secret child of a working-class Zaunite family produced someone whose first instincts are all communal — protect the people around you, use what you have, don't let the powerful step on the people they consider disposable. Zac's elastic, regenerating body and chemtech-derived strength make him a formidable protector. His upbringing made him want to be one. The two combined into someone the undercity genuinely needed.
He was eventually discovered by Zaun's chem-baron establishment — the people who would love to have a weapon made of experimental chemtech working for them rather than against them. He has declined, repeatedly and with increasing force. Zac's loyalty is to Maline, Zaun, their community, and by extension everyone in Zaun's undercity who is in the same position his parents were: doing the right thing with insufficient resources, hoping it's enough. He is trying to make sure it is.