The Royal Lieber Academy, one of the "Three Great Magical Academies."
Royal Liber Magic Academy

The Royal Lieber Academy is where Magi of the "Paladin" class and other high level Magi. It is the kind of place that wouldn't give in without putting up a fight.

The academy was segregated into another dimension and encased by a giant barrier, suspended in a space between parallel universes. Most of the students and faculty have been turned into Demons, disintegrated via Breakdown Phenomenon or simply killed.