The Medallion is a long Family heirloom passed down generations of the royal family. Jircniv Rune Farlord El Nix wears one under his garments. Though it's said that the medal is effective precisely because people did not know it was there in the first place.
The medal possesses magic that gives one mental protection, however, its power seems to only provide protection so long as the wearer keeps his/her mind focused. With this, the mental barrier is enough to ward off Demiurge's mind control so it can resist any mental attack that is at least up to level 40.
- The Bloody Emperor keeps the knowledge of this item as a secret.