Heart of Ayrsai

10th-Level Druid, Circle of the Winter Pheonix Feature

When you lose your wild shape or animalistic form (either by dropping it or losing hitpoints) the winds of winter howl and you burst with cold energy. All creatures within 15-feet of you must make a constitution saving throw (vs Spell DC). Taking 3d8 Cold damage, and their movement speed is reduced to 0 on a failed save, or half as much damage and their movement speed doesn't change on a success.