Osteogenesis Imperfecta

Osteogenesis Imperfecta, commonly known as brittle bone disease, grants your cat +2 Bruise, +2 Bleed Thorns, and +2 Thorns. Bruise means your cat takes 2 extra damage from every hit, making it significantly more fragile. However, Bleed Thorns and regular Thorns cause attackers to suffer Bleed and direct damage whenever they hit you, punishing enemies for targeting your cat. This creates a glass cannon defensive profile where your cat is more vulnerable but automatically retaliates against attackers.

Osteogenesis Imperfecta is heritable and can pass through breeding. It can also be acquired through events or applied with a Disorder Syringe from the Organ Grinder. The +2 Bruise penalty is significant since it effectively reduces your cat's effective HP pool by making every hit hurt more. Combined with the Thorns and Bleed Thorns, the disorder turns your cat into a damage sponge that hurts enemies back but may not survive prolonged focus fire.

Strategically, Osteogenesis Imperfecta works on cats with high Constitution or Shield stacking that can offset the Bruise penalty while still triggering Thorns damage on attackers. It pairs well with healing-focused support or items that grant Shield at the start of each turn. Avoid it on low-HP cats or those without defensive support, as the +2 Bruise will cause them to go down quickly. In fights with many weak enemies that attack frequently, the Thorns and Bleed Thorns can rack up substantial retaliatory damage without the cat needing to spend actions attacking.