Monument of Atonement

Shadow Magic: Monument of Atonement (影魔法『贖罪の碑』) is a Shadow Magic spell.

Description
With an open grimoire, the user creates two halves of a large black tomb above and below the user and the target. The top half of the tomb has a large gravestone decorated in runes. Hands of shadow reach up from the bottom half and restrain the user and target, as well as pull down the top half. As the two halves meet, anyone inside is trapped within a shadow world that does not physically exist and contains no light, life, or death. The tomb then sinks into the ground and becomes a large seal.

This spell requires an immense amount of magic power, on par with a highest-ranking devil, and risks the user's life since they are trapped along with the target.

Despite the spell's strength, powerful magic attributes that can affect invisible concepts could be used to breach the seal. If broken, the seal expels everyone trapped within.