This crystal can be used as a spellcasting focus to substitute the material components specified for a spell unless a cost is indicated. You must have a hand free to use the crystal. 

Seductive Mirage: Once per Short rest, you can cast the disguise self spell. Your appearance will be changed to the ideal desired physique of a person you can see or are acquainted with. 

This crystal has a crimson hue and exudes an otherworldly warmth. At first glance, it appears adorned with intricate depictions of revelry and jubilation — a mesmerising dance frozen in time. 

However, on closer inspection, the scene is tainted. Many of the depicted figures wear grimaces of agony and dark horns seem to emerge from the skulls of some of the dancers.