The Sword of Alexander.

Orichalcum is a mystical metal material that gives great powers to the life form that possesses it. Many Eons ago, the Orichalcum was split into three and landed on Earth. The metal then took the form of three relics: Skanda’s Vajra, Jew’s Cross, and the Sword of Alexander. Anyone able to re-unite these three Orichalcum relics would then obtain the powers of a God. Now two rival aliens are in a heated race to reunite the Orichalcum. They land in Edo era Tokyo where the relics are thought to exist.