The reaction isn't immediate, but it is thorough. Chara's cheeks stain red. They turn towards Frisk with their lips peeling back, and their eyes are burning with outrage and offense.

"You don't know me," they snarl. "You don't--know anything, where do you--get off saying--"

Words are failing them. They're struggling, and they want to punch Frisk right in the teeth. The other fist could reach their hair and yank like they're starting an outboard motor and bring Frisk's face right into the bars and then they'd be in reach and it'd be over and Chara stumbles to their feet, world turning around them like they're drunk.

They stagger back to the bunk and curl up in a ball that's nothing so much as it is coiled rage and gnashing teeth, and they hate Frisk, they hate them, they hate them they hate them--

They muffle their face against their arms and knees, and heave a breath into their lungs, and it feels like the resulting shriek is a wedge being driven into their own ears. They can't stop shaking, and they're not really aware of the way their hands are digging vicious claws against the thick cloth of their uniform pants.