Claw Retraction

The power to instantaneously extend one’s nails into sharp claws. Also known as Nail Extendibility

Capability
The user can grow bone-like claws and retract them. The user's fingers dynamically generates calcium and iron to extend forth sturdy light-weight nails. Can be used as tools or weapons. Can retract these claws, absorbing the calcium and iron back into the body.

Techniques
Some can perform “projectile”: to launch appendages (nails, feathers, scales) like arrows.