Cersei’s personality undergoes a dramatic transformation over the course of the story. Once a calculating, power-driven strategist, she gradually becomes a ruthlessly paranoid, isolated, and increasingly autocratic ruler. Viewing nearly everyone as a potential threat, she comes to rely on fear, intimidation, and unchecked cruelty to maintain control, abandoning whatever restraint or pragmatism once tempered her ambition. Unhinged cruelty, and deep-seated megalomania is what she displays at her worst. Her appearance shifts from the opulent, flowing gowns of her early days to a dark, severe, and militant aesthetic now that she's the MAD QUEEN.