Description

 The monster Gyaos has attacked Tokyo, and the giant monster Gamera appears to confront it! 100,000 years before the world was thrown into chaos by monsters, there existed a kingdom with a certain super ancient civilization. While the kingdom reaches its peak of prosperity, the problems of a 250-year long war, population explosion, and accompanying food crisis progress to a point that cannot be ignored... In order to solve these problems, the kingdom creates a certain "super-giant creature", but the creature leads a boy to tragedy and turns him into a terrifying scientist.

Maybe coming in

Gamera -rebirth- Code Tersos Chapter 8

Gamera -rebirth- Code Tersos Chapter 9