Gigantic Formula

Gigantic Formula (機神大戦 ギガンティック・フォーミュラ, Kishin Taisen Gigantikku Fōmyura) is a Japanese anime series that aired in in April 4, 2007 by TV Tokyo. A manga adaptation by Shōhei Oka was serialized concurrently in Dengeki Daioh.

Plot
2035 A.D. The heads of ancient giant idols were excavated all over the world. Using those twelve stones statues, humanity had barely overcome the threat of extinction called the "Equatorial Winter". But on the other hand, the stone statues also forced humanity to construct colossal suits of armor as their bodies and demanded that the humans fight each other.