Mal had been playing a dangerous game by positioning herself against the Dark One, and she had known it. Apparently, her bringing Cruella and Ursula into the town and reviving her mom was was something unforgivable. Probably because her mom was now significantly weaker since the magic had passed onto her and didn’t want to return to the past owner and because her mom seemed to have no interest in aligning herself with the man who created the curse that separated her from her kids. Go figure, there.
The Dark One had lured Harry out to the edge of town, to the barrier. No doubt because he knew that she could go after him to retrieve her friend. And she did just that, knowing full well that it was a trap. She didn’t like letting people know just how powerful her magic was. It generally made them lump her into the same category as the Dark One himself. When the fight broke out, she was able to hold her own more or less. Her lack of proper training was what was making the difference, ultimately. But she was fine, all in all. That was, however, until he saw him send something toward Harry. Shifting gears, she immediately went to defense, trying to send that attack back to Rumpelstiltskin, but he was already preparing another attack. A blast of wind knocked her into the air and to the side, through the barrier, and into a tree. She yelled out in pain as she made impact, falling onto the ground. Slowly, one of her hands went to the back of her head before she aimed her eyes toward where she had flown from, a look that could only be described as confusion.