Disappearing Treasures

Adora finds some kind of crystal (?) which she shows to Glimmer and Castaspella. The latter uses her magical power to protect this treasure from evil. Then, the three get back into the palace and leave the treasure chest outside. Catra steals it. Because of Castaspella's magic, the evil one now sees her own reflection in the mirror to be really old and ugly. Shocked by that, Catra drops the crystal in a pond. She-Ra finds her there, rendered helpless by Castaspella's magic. She-Ra frees her though because she thinks even evil beings have the right to live.