Chain of Geng Yijun

The Chain of Geng Yijun is a piece from Xebli mythology, a chain made of thick silver that the titular Geng Yijun used to capture a great beast. He delivered the captured beast to his patron, who trained it to guard his treasures.
It is unclear whether the chain truly existed, though Geng Yijun was a historical figure who lived from 3320 to 3353 EC, before being slain in battle.