Talk:Cutie mark/@comment-71.188.56.232-20130416192926/@comment-192.152.5.236-20130521174229

The reason why she can become a shadow is because of an evil spell. One night (before luna became nightmare moon) she cast a spell that she found in an old book. It was meant for someone else, but when she cast the spell on herself she became a shadow and ever since that day, she can take on the form of a shadow at night.