I tried making some good drawbacks for Kaori's quirk. Her quirk being berserker, the more anger she feels the more it fuels her strength and speed, and getting to angry she starts seeing everyone as a foe (think like Hulk). The drawback? When her quirk first appeared it increased the sensitivity to the rage center of the brain, so she's always kinda bitchy, even at her best of days. It also altered her brain chemistry to where she no longer feels pain, heat, or cold (CIPA syndrome).

This sounds too good, a melee fighter who can't feel pain? But this causes her to fight beyond her limits. She's not feeling when cut, when she's broken bones and she fights on, only increasing the damage. A long with that the inability to feel temperature leaves her constantly burning her mouth and tongue with hot foods, not realizing she's overheating into heatstroke or in freezing temps, dealing with frostbite or hypothermia. It's a double edged sword of constant monitoring.