He used to be a doctor. He has excellent marksmanship skills and knowledge of weaponry, picking off one by one the soldiers who kidnap the children, and setting explosive traps within the city. He provides the children with shelter and food and treats their wounds, asking for help with finding and exterminating trespassers in exchange. He believes that every person carrying a gun does so with the intent to kill, and must be eliminated.

Spoiler

The meat he and the children eat comes from the bodies of those he has killed.