Supernatural Era

His name was John Smith, and later he was known as American Guardian. Sophia was amazed by seeing the footage, when seeing once a humble soldier transformed into a super mecha soldier.

And with his strong armor and stamina, he participated in the war, saving many people and confronting the nefarious forces of HAVOC, led by the ominous Blood Skeleton.

Blood Skeleton also gained the superpower from the same experiment, from which John Smith gained. But instead of looking good like John, Blood Skeleton looks like a ghost.

And he also became mad with the power. He found a magical cube known as the Astra Cube. And using it, he has gained the advanced weapon.

For saving his country, and defeating the Blood Skeleton, the American Guardian chose to sacrifice himself. Erased from history, now, no one knows if John Smith is still alive or not.