"All right, the biggest problem before you now is that you have no idea whether your own sanity is excellent or already on the verge of rampaging."
"I imagine it's hard for you to notice. After all, by the time you can truly detect something abnormal in yourselves, your sanity will already be very, very low."
"So, this course has prepared dedicated Sanity Measurement Crystals for you. They're right in front of you."
Lu Yuan did as instructed and placed his hand over it.
The crystal was slightly cool. After a few breaths, color began to bloom within it.
His was pale yellow, somewhere between green and yellow.
Lu Yuan calmly swept his gaze around.
Large swathes of yellow filled the classroom, yellow in shades both deep and light.
Closer to the front, several crystals showed red through their yellow.
"I'll briefly explain the colors. You don't need to remember them too precisely." The Lantern Knight's voice came from the podium.
"Green is exceedingly rare, practically impossible to see. The transition between yellow and green is very good. Pale yellow is considered decent. Darker yellow is still acceptable. The transition between yellow and red is very wrong. Red is very bad and requires rest."
"Those of you who have already begun to turn red, put your other classes on hold for now. After class, report to the Academy Recovery Area. There are places there specifically meant to help you restore your sanity."
At the side of the podium, the Lantern Knight's gaze swept across the classroom before stopping somewhere.
"This student."
Lu Yuan followed his gaze.
In the front row, a girl's crystal was a perfectly clean green, without the slightest impurity.
Lia.
"Your sanity is actually green." The Lantern Knight seemed somewhat stunned.
A low murmur of amazement rose