Brittle Bones

You target a creature you can see within range and attempt to transmute its physic into a more fragile material. The target must make a Constitution saving throw. On a failure, the target is vulnerable to bludgeoning and thunder damage. If the target fails by 10 or more, the target is incapacitated as soundwaves reverberate through its entire body, dizzying and disorienting it. The deafened condition nullifies this effect. At the end of each of its turns, the target can make another Constitution saving throw. On a success, the spell ends on the target.