What is the significance of the red mark on Gang Shou's head in the Five Dynasties?

The mark on Gang Shou's head is that she sealed chakra on her forehead because her brother and lover were killed by orochimaru. Seal your strength and make a mark on your forehead. Also, once the seal is opened, it is a technology, as if a large number of technologies have come out sharply in chakra. It is very powerful.