Being forced back from Sam hadn't helped much. The hold Peter'd had on his arm had been ripped away by the telekinetic shove, the claws being extracted from Sam's body in a ripping-and-tearing sort of way.
He had an instant to recover his footing before the bright light swallowed him. Each cell in his body screamed in pain, died, and was replaced, still echoing the cry of pain.
Peter was on his knees when he could see again, ears pounding from the shout his throat had let fly. Without pausing, without stopping to catch his breath, he launched himself back to his feet, stumbling as he tried to lock eyes with Sam again.
"Have to do better than that."
Then lightning flew from each of his hands, bolts aimed at Sam. He could feel Claire grasping at his mind, trying to see how he was, wanting to help. Stay back, he sent, to both her and Nathan. Let me handle him.
The underlying dread was that they would join the fight. And then Peter would have to forget about Sam Winchester, and devote all his energy to stopping the things this demon holding him was doing, whether it killed Sam or not.