Scenario 1: The murder time trio were causing chaos in an AU and the star sanses showed up to stop them, Killer ended up getting hurt and taken by the star sanses.
Scenario 2: Killer was walking around an AU, looking for anyone that was alive that he could kill. He eventually found dream, or what they now like to be called, Shattered.
((Shattered!Dream x Killer))Scenario 3: Custom.