See Chapter 1.
As was commented elsewhere, that the mere thought and idea of a super powered Harmony in Sunnydale would be deliciously evil, here's a slight rewrite of the section with her fate of the evening. Poor poor Sunnydale...
I kept most of the section for the context
Xander came to, finding himself with nothing but air under him, and did what anyone would have done in his case. He started screaming. Under the circumstances no one would blame him for that, then again, no one else heard it. Eventually Xander plummeted into the Sunnydale harbour, sustaining remarkably few injuries as a result.
The girl was less fortunate, and ended up flattening an unlucky guy just waking up on the pier. Her injuries should have been quite fatal, but she too ended up with only minor injuries. The guy however...
Warren Mears barely had time to register the buxom blonde girl heading towards him at high speed, screaming loudly. Warren died, touching a girl for the first time, though probably not in the way he had always dreamt of.
Inadvertently Harmony had managed to do more for humanity in that instance, than she could ever have imagined doing previously in her life, of course, as her idea of the pinnacle of human achievement was the latest colour nail polish, that wasn't saying all that much.