Kibisis

Kibisis is the name of the magical artifact that was used by Perseus to slay the Gorgon Medusa. It is a magical sack woven from clouds that could turn into a radar-like polished bronze shield, personally created and charmed by the goddess Hera.

Abilities
The Kibisis is an extremely powerful sealing artifact that distorts the concept of the world through a mirror world-type Bounded Field that places the inside of the sack on the outside and the outside of the sack in the inside. When it was used by Perseus, creating a fold in space that placed the outside world into the inside of the bag, reflecting Medusa's gaze back toward her as if reflected in a mirror, allowing him to slay her with the Harpe while she was immobilized.

It could also transform into a polished bronze mirror-shield, capable of reflecting everything it gazes upon. Acting like a sort of detector that possesses sonar and radar functionality, it reflects the surroundings onto itself, showing the layout of an area and the heartbeats of any life present in the location.

Trivia

 * Kibisis is based on Kibisis and Perseus' bronze shield from Fate/Prototype.
 * Unlike traditions where the pouch and the mirror are two seperate items, the Kibisis was in fact a single item that was splitted into two due to mistranslation.
 * The Kibisis was used as a blueprint/inspiration for Hephaestus to create the Aegis.