Through the Looking Glass

Through the Looking Glass (常競合の全反射鏡 (スルー·ザ·ルッキング·グラス), Suruu Za Rukkingu Gurasu; lit. "All-Reflecting Mirror of Eternal Confliction") is a powerful Combination Magic spell that utilizes aspects of both Mirror Magic & Reflector in order to be properly invoked. It's considered to be one of the few spells ranked as an Ancient Spell due to how long it's existed.

The exact time of creation being unknown, it's hinted that it was during the time when magic was still being developed. It's known that this spell has various functions, but the main one is fixated on the concepts of the composite magics used to create it.

Currently, it's unknown how many users are able to utilize a spell of such caliber — but it's hinted to be very few due to the information pertaining to it being nearly lost.

Trivia

 * This was based off of Mirror Alice from the light novel series, Highschool DXD.
 * The name of this spell is derived from the alternate name for Alice in Wonderland.