Sealing Crystal

Sealing Crystal is a magic item that can seal high-level spells.

Description
By YGGDRASIL standard, spell-sealing crystals were one of the rarest among magic items out there. In turn, they were also very easy to use, and at high levels they were employed in large quantities.

In the New World, sealing crystals are looked upon as legendary items imbued with great power. The legends and tales revolving around these items originate from the Slane Theocracy. According to Ainz, Sealing Crystals were valued as rare items that cannot be easily obtained or found in the New World. In a way, there are very few people like Ainz who actually knew about the true potency of its effect.

As a result, false tales regarding the Sealing Crystals can be fabricated in the interest of its owner to keep the secrecy behind this item confidential. This item was also one of the national treasures possessed by the Slane Theocracy. The Sealing Crystal was left behind by the Six Great Gods six hundred years ago until the Theocracy's higher-ups pass it on to the former holder Nigun Grid Luin during his mission to assassinate Gazef Stronoff. He would later use it in a failed attempt to defeat Ainz Ooal Gown by summoning a high-rank angel.

Appearance
Sealing crystals seem to come in a variety of shapes and hold a quality of brilliance depending on what types of magic they contain.

Abilities
Sealing crystals are incredibly powerful artifacts in the New World, as they are capable of containing tier seven or higher magic, an impossible feat for humans who are unable to contain or cast such magic. Thus, sealing crystals are considered extremely valuable to any nation that possesses one. The magic released by a sealing crystal can only be used once, so holders of these items would only use them as a last resort.

Afterward, one must go to great expense and perform extensive rituals to recharge the spell within the crystal.

Trivia

 * Magic Casters, on the New World, highly prized these sealing crystals as they are a subject of much debate and study.
 * In the official manga, the Sealing Crystal was shattered into pieces when the summon it held was released from confinement.
 * Ainz determined from the brilliance that the crystal Nigun used is unable to hold magic over the 10th tier, Super-Tier Magic.