I don't own any of the characters, and I'll be blaming caffeine deprivation for this to my last breath.
BtVS is owned by Mutant Enemy and Joss Whedon (I think)
Superman and other DC Comics characters belong to DC Comics.
Superman was following Supergirl back towards the town they had both found themselves in an hour earlier. At least the time had been well spent in the company of his cousin, having dispatched several types of aliens and unknown monsters, saving a lot of people.
That's when a wave of magic flowed over them both, so fast that neither had a chance to get away from it.*****
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 were quite fatal.
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 death, than she could ever have imagined doing in 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.*****
Willow came to taking stock of her surroundings, pleasantly surprised that nothing had happened to her body while she was a ghost. The ghost sheet costume was gone though, and she was mortified to find that her Zatana costume was quite visible, and that she seemed to fill it out a little more than she remembered when she put it on at Buffy's house. Reaching up to remove the hair piece, she was horrified when it wouldn't come off, she even tried pulling at it hard, that is when she saw the colour, she was no longer a read head. That realization overwhelmed her, and she fainted.*****
Oz noticed the pretty girl fainting on the porch, and decided to stop and get her to safety. Sunnydale was not safe at night. He didn't know why, he just knew.*****
Buffy just woke up on her couch, wondering when the servant girls would come get her out of her dress.*****
Spike, Drucilla, Angel and innumerable other little piles of dust was wondering if this was what the afterlife was like for vampires.