However, the use of Photon Swords, and experimentation was soon outlawed after the Battle of AIS, when demonstrated by Cody Cuidightheach using the Photon Sword called Excalibur to easily slice through an IS with depleted-barriers with ease, destroying both the IS and the pilot. Another reason it was banned is due to the capabilities of the sword itself. Easily able to slice anything, it could also be used to slice into vault, and get sensitive data. Due to this, the lead-designer, Samuel Hayden, payed dearly for the construction of the experimental weaponry by the Alaska Treaty by the Japanese and the Australian governments.
The Photon Sword is a type of energy weapon using photon particles, and plasma. It using an rare, non-earth mineral called Defigo, which focuses the photons into plasma, and then somewhat "crystallize" into a blade, which is able to slice through almost any physical matter, including the barriers deployed by the Is.