Before Twilight was even aware of what was happening, she made up her mind. Her body disappeared into the ether, vanishing into a world of magic. The world was constructed out of nothing but magic, so it was a simple matter of accepting that fact, letting that truth enter her, become her. She crossed the distance between herself and Nightmare Moon in a fraction of a second, her body becoming awash with tingles as she passed through Celestia's shield.