She didn't seem THAT traumatized by the brother, honestly, but she sure did with the gang rape.
Anyway, I feel like the Stalker and the Prince are the same person as well.
This whole manga is a complete mindfuck though, I honestly have no idea what's going on. Is she asleep in a coma? Is the brother in a coma? Did she die? Has the sleeper awakened? Is it aliens? I understand if like, aliens took all the people away, but where'd the CARS go? How does scratching in the dirt change the landscape? How did Porky vanish when she dunked her head underwater, and how do all these people keep showing up ahead of her?
It really kind of does feel like a purgatory type experience. Also the smut levels here are amazing.