Patchouli Knowledge is a magician who excels at spirit magic. She lives underground in the Scarlet Devil Mansion’s Great Library. Supposedly, the library can get rather hot in the summer, but Patchouli knows a way to enjoy reading and teatime without breaking a sweat, no matter how hot it may be outside.

Summer Cooling Magic - Indoors Edition
“You can cool down a sweltering room by using water or ice magic to produce cool air. However, care must be taken to scale the magic’s power according to the size of the room. There have been reports of blizzard-like environments being created, leading to horrific cases of indoor frostbite. Magic that chills drinks and magic that temporarily changes a room’s interior design to produce cooling effects are also recommended. During our research, we also encountered a magician who said her cool-air-producing magic item was enough to get through the summer, but such a claim has not yet been verified.”
[Excerpt taken from a book for magicians.]

“It’s so hot…” Patchouli was busy reading like usual, but the heat was getting to her.
The library was so hot, in fact, that she wondered if someone hadn’t been using fire magic in the mansion. There was no way she could enjoy her book like this, let alone the tea and sweets Sakuya had brought her. Even the countless rare books lining the shelves would begin to degrade at this rate.
“Looks like I don’t have any other choice…” sighed Patchouli, having decided what to do.
Library interiors don’t tend to change, especially not on days as hot as this, but the Great Library’s interior began to do just that.

The heat from before began to feel like nothing more than a bad dream. Situated below ground in the Scarlet Devil Mansion, the Great Library was now perfectly cool. Thanks to Patchouli’s magic, the dimly lit aisles and stylish decor had been replaced with a bright, oh-so-inviting ambiance. Patchouli looked around and smiled, marveling at her own brilliance.
“Even my tea and sweets are refreshingly cool.”
The spirit magician turned the pages of her book, which were slightly cold to the touch, and continued to make the most of her tea time. All of the mansion residents and servants who entered the library were taken aback by its new look. Supposedly, Patchouli even greeted them with a little more kindness than usual. It seems a pleasant reading environment can really work wonders.

The Great Library was ordinarily quiet, but right then, it was full of life. Remilia and Flandre were enjoying the cool air and helping themselves to tea and sweets, while Koakuma was feeling overjoyed at how well her bookshelf organization was going. Sakuya doubted whether this was the best use of magic, but as she carried in an extra trayful of tea and sweets, decided it was fine once in a while. As gatekeeper, Meiling perhaps shouldn’t be taking unscheduled breaks, but she came running into the library all the same. It seemed the Great Library was set to be that summer’s go-to hang-out spot.
“I just wish you’d all take a little more interest in reading…” muttered Patchouli.