Helena got to the roof soon after Xander did. She waited a little before stepping out onto the roof, approaching slowly, waiting to see if he was going to be able to snap out of it by himself or not.
Xander was still clutching at his head, the pain not even subsiding a little. It wasn't working, why would he think this would even work? Damn it! Just another mistake, she had to come back and remind me of them! What does she want!? Why won't it stop!?