Avidya World. It looks like your typical final boss dungeon, with creepy music and dark, distorted halls. But if you look at the doors closely enough, you'll notice that Avidya World is a twisted version of your school. And nearly all the doors of the "normal" school refuse to budge now...
That's because Avidya World is essentially Maki Sonomura's brain housing her worst inner demons mixed with the school dungeon layout. It's fitting on a thematic level.
