About Starlight's powers... one can assume that Twilight is still coming into her own as an alicorn. She's not at the level of the other three yet. And we can assume that Starlight studied different areas of magic than Twilight. I mean... how did Twilight not know about a spell that could remove cutie marks? Does Celestia know about such a spell? Do Luna or Cadance, for that matter? Did Starswirl know? Did Starswirl originate the spell? It doesn't seem like something the alicorn princesses would know about or use. It seems like forbidden magic. So how did Starlight come by it?