Sometimes referred to as the "Holy Container", the Light Container has a bizarre diamond shape to it and has a dark shade of blue and indigo on its outside. The inside is a distorted color when it contains the holy properties of a person which can be either pink, purple, yellow, or green.
The Holy container is a container that was created by the Church, specifically by Valper Galilei during the Holy Sword Project, who used the Holy container to store the light properties of countless Human victims after extracting them from within. This was done so in order to create artificial Holy swordsmen who were capable of wielding even the strongest Holy Swords in existence like Excalibur.
The Holy container, was used by the Church during a ceremony, held in order to make Irina Shidou, a Holy Sword wielder, which later reveals that she was able to wield Excalibur Mimic because of it. The Holy container was also used on Freed Sellzen extensively, as he had been able to use four Excaliburs at the same time.
The Holy container makes its final appearance during the battle between the Gremory team against Kokabiel, Freed, and Valper, being thrown away by Valper, which was picked up by Yuuto Kiba, who was able to use it to gain his Balance Breaker, Sword of Betrayer, due to the fact that the Holy container contained the light of his former comrades, from the original Holy Sword Project and that the spirit of one of his former comrade gave him his second Sacred Gear, Blade Blacksmith.
Light Container: The Holy container is able to contain the light of a human.
Holy Sword wielding abilities: When used the Holy container is able to grant a regular human the ability to wield and use a holy sword.