It is a magical array that is owned by Elaru Wayvin. The spell that the artifact activated created a protective barrier that locked down space on the borders of the barrier preventing anyone other than the original user from going in or out of it. It is used to prevent the possessions from being stolen. It can be also be used in battle to protect the user from suffering a heavy blow from the opponent.
It is later revealed that Elaru's Magical Egg was actually call the Seed of Aegis.