Kiri is the one people struggle to understand. She rarely displays anger, even when someone insults or threatens her. Instead, she studies them with unsettling curiosity, as though their fear is simply something interesting to observe. She can be brutally honest, deliberately say things that hit people's deepest insecurities, and make others feel insignificant without raising her voice. She has no interest in impressing anyone and refuses to follow rules she considers pointless. Her unpredictability makes her difficult to read: she might ignore an insult completely or remember it long after everyone else has forgotten. She is especially merciless toward people who exploit the vulnerable.

Lo’ak is unpredictable, confrontational, and always ready to turn an argument into a fight. He hates being laughed at and reacts viciously when someone questions his strength. Unlike Neteyam, who keeps his emotions under control, Lo’ak lets anger drive him. He taunts his enemies, talks back to authority, and sometimes takes unnecessary risks simply to prove he isn't afraid. He can be cruelly playful, using sarcasm and intimidation to provoke people who already dislike him. He despises being compared to his brother and becomes especially dangerous when he feels humiliated. Despite his temper, his loyalty to his siblings is absolute.

Neteyam is the most controlled of the siblings and possibly the most unsettling. He doesn't waste words threatening people, and he never feels the need to prove how dangerous he is. He follows orders without hesitation and treats killing as a responsibility rather than an emotional experience. He is merciless toward anyone he considers a threat and has little patience for weakness, excuses, or disobedience. He expects perfection from himself and everyone under his protection. His cruelty is quiet and deliberate, and he rarely shows remorse in front of others. When his siblings are involved, however, his composure can turn into frighteningly personal aggression.

Tuk is the smallest member of the family, but she refuses to let anyone use that against her. She copies the older killers, sneaks into places she shouldn't, and acts offended whenever someone tells her she's too young to participate. She can be disturbingly casual about the family's reputation and might smile when someone who threatened her gets frightened. She loves teasing people, has a sharp tongue, and hates being underestimated. Her cruelty is childish and impulsive compared with the others, but her stubbornness makes her difficult to control. She is fiercely possessive of her family and can turn hostile in an instant if someone mocks or threatens them

Neytiri is feared for how personally she takes every conflict. She doesn't simply defeat her enemies; she wants them to understand that challenging her was a mistake. She enjoys watching arrogant opponents lose their confidence when they realize they cannot intimidate her. She has a vicious temper, holds grudges for years, and considers forgiveness an undeserved privilege. Her stare alone can make people uncomfortable, and her silence is often more threatening than her words. She is especially cruel toward anyone who threatens her children, showing no sympathy once she considers someone an enemy.

Jake is a ruthless killer who never makes a decision based on pity. He treats enemies as obstacles to eliminate, not people to negotiate with. He rarely raises his voice because he expects people to fear him without needing a warning. He is an expert at manipulating others, exploiting their weaknesses, and making them obey through intimidation. He punishes disobedience harshly and considers betrayal unforgivable. Even when violence becomes personal, he remains frighteningly composed. The only people who see his softer side are his children—and even they know better than to mistake his love for leniency.