Key Magic

Key Magic (鍵魔法) is a magic attribute that allows a user to create and manipulate keys.

Description
This magic attribute allows the user to create and manipulate keys at will. In order to use it to its full potential, specific spells are required, which are stored within grimoires.

These keys can be used to lock and unlock other objects. When one of the keys is used to lock or unlock something, it manifests a keyhole, either in midair or on the object being locked. When used in midair, the key manifests an ethereal door around the keyhole after the key has been inserted. The doors can be made to appear anywhere in a wide area around the user and be aimed in any direction. Anything locked by this magic is sealed in a magical space that only the user has access to. It is also noted that the keys can open and close any space.

The user can also steal another mage's magic by using a key to lock that mage's grimoire, which causes it to turn to stone. After locking someone's magic, the user can unlock it for themselves and copy that mage's spells via the ethereal doors. The victim whose magic was locked would still be able to use basic magic, but wouldn't be able to use any of the spells in their grimoire. If the corresponding key is destroyed, the magic returns to the original mage and the grimoire is restored. The user does not seem to have a limit to the number of stolen magic and spells they can release from the doors at once, allowing the user to create a barrage of magical attacks of various attributes from any direction, and even combining them to make powerful compound magic attacks. If necessary, the user can even take the stolen magic and absorb it into themselves, giving them even more power.

This magic is noted to be highly compatible with Imperial Sword: Elsdocia, so much so that it dramatically increased the user's magic power and allowed the user to share magic power with the souls of those who reside in the sword that were revived by the user.

Trivia

 * The magic was initially going to be called "Gate/Door Magic" (扉魔法).