The kaguyas were a clan who were considered warmongers, they could only find their true peace and ease their mind by killing and fighting constantly. Sadly they met their demise at the hands of the Village of the mist who they went to challenge they were all but slaughtered but only one survived the slaughter that being Kimimaru. There is little to no information which refers to the Kaguya clan, thus far this is all that we know about them.
They have an abnormal bloodline limit which involves their bones. They are able to change their skeleton frame anyway they wish. They can increase the density and calcium to harden their bones to make them harder then steel.