Seven Seal Magic

Seven Seal Magic is an ancient magic created by the primordial gate keeper (aka the person who forged the celestial zodiac keys) there are 16 keys total consisting of 7 angels 7 devils and 2 extra keys to summon demon king and angel queen. instead of summoning spirits this magic summons angels and devils.

Description
 seven seal magic, as stated above, is used to summon devils and angels, however, the demonic and/or angelic spirits summoned from the seal keys each represent a different one of the seven deadly sins or seven heavenly virtues. There are 16 keys in all, the seven sin keys are small and made of obsidian the seven virtue keys are made of pearls (the angel queen key is a little large but also made of pearl and the devil king key is also a little larger but it's made of obsidian), with a jewel embedded on the end opposite the teeth. The color of the jewel depends on if it's a devil or angel that the key is linked with. The keys are also notably larger in comparison to most celestial spirit keys. Compared to normal Celestial Spirits like the Silver and Zodiac Spirits, 16 seven seal magic keys are much more influential, for example if the wizard has a sin key the devil linked to the key will tempt them into committing the sin the key is attached to and the angel will guide the wielder to the virtue they represent, so it takes a mage of considerable skill to be able to wield one efficiently and make them obey their orders. every corresponding set of a devil and angel is  a seal, such as if a wizard wields both the angel of chastity and the devil of lust they hold the first seal, and if a wizard manages to hold one seal they could summon a being that represents both the devil and angel in a fusion more commonly known as a divine seal guardian. devil and angels often call their key holder keeper in order to honor the fallen the primordial gate keeper.

The Seven devil
