Kiryou (キールウ, Kīru-U) was the legendary Beast who created by Samuel. After event of Invasion of Navi, Samuel molds his stone into Keystone to prevent his hatred of himself as Sadako/Samara.
Seal into Creation
After the Keystone overpowered Sadako/Samara and sealed, the Keystone curses her into a core within itself. The sinster prevented the seal of Keystone to get rid of it. However, nothing work and worser than dark mojo and mutated version of herself. She remained, frozen inside Samuel's Keystone for entire sealed.
The Birth of Kiryou
During the battle against Geysar, a frozen Keystone was desealed by awakened mojo power and ultimately formed into a creature like-banshee nickname Kiryou. She gain ability to absorbs the entire three planets to recreate a renew body. However, her renew body was destroyed and sealed by Samuel for good.