Well, she'd found the Alicorn Amulet, an ancient relic of great and terrible power that strengthened her magic to absurd levels. She managed to overcome me with it and forced me out of Ponyville, after which she took over the town. She was being corrupted by the Amulet to become not only stronger, but also genuinely evil, and there didn't seem to be much we could do to stop her.

But I made my way to Zecora's, and she showed me some new tricks I could use to take her on. I eventually tricked her into thinking I'd found a powerful amulet of my own, and she took off the Amulet and stole mine. But mine was a fake. Just one of Zecora's doorstops.