The Brave Fighter of Legend Da-Garn (1992)

Seiji Takasugi gets a jewel called the Aurin Witch that is Earth's alter ego which chooses him to be the commander of eight brave robots. The robots are sleeping in various parts of the world and are 'Brave Stones'. But then they become modern robots by fusing with people and machines once they are awakened by Seiji by following his instructions. The enemy is Lord OhBoss and he wants to steal the earth's energy.