Talk:My Little Pony Equestria Girls/@comment-11111343-20130807033653/@comment-5837525-20130807074748

Okay, here's my theory: the Element of Magic can still function without the other Elements of Harmony, but not in the same way as when they're working in tandem. That's why Twilight was able to (unintentionally) use it to switch her friends' cutie marks in Magical Mystery Cure. The other Elements of Harmony are dependent on the Element of Magic, but not the other way around. It's like the Elements are a circuit, and the Element of Magic is that circuit's power source.

Now, as for the magic of friendship: remember when Twilight said "the magic contained in [her] Element was able to unite with those that helped create it"? And who created the Element of Magic? Twilight's friends, through the Elements of Harmony. I think Twilight's human friends somehow tapped into the magic of friendship through the connection between their world and Equestria via the portal. When the portal opened, some of Equestria's magic leaked through to the other side, allowing them to harness the magic of friendship. When the portal closed, that connection was severed.

That's the best I can come up with.