Amethyst crystal rise is unlocked at rank 20 of the free track of Luminous Night. Once unlocked, it can be equipped in the "Healing Flairs" section of the cosmetic tab in the inventory.
Amethyst crystal rise is a healing flair, meaning it activates upon use of the health potion. Once activated, a large amount of amethyst clusters sprout from the ground while multiple pink and purple rings rise up around the player's body. After a short duration the effects disappear. As is the case with all flairs, amethyst crystal rise's effects are purely cosmetic and have no other gameplay functionality.