Gadvia

Hundreds of years ago, scientists discovered Blue Crystal — a powerful new energy source that drove a rapid technological boom, allowing humanity to reach space and the deep sea. But overuse of crystal energy awakened the primordial gods of Earth, who unleashed a flood that submerged all the continents and sank civilization to the ocean floor. Survivors rebuilt on deserted islands and returned to faith in the gods. Then the waves brought something unexpected ashore: a girl from the deep sea who calls herself Limnoreia, sent to the surface with a heavy burden — to find a way to save the resource-depleted sanctuary she came from.