Bro what?? Why would he think she'd rebound with the evil supervillain that tried blowing up the city and tried to kill her boyfriend multiple times he truly is insane
To be honest Eradicator committed treason by striking Superboy. Superboy aka Kon-El is a legitimate family member of the House of El. Eradicator is sworn to serve the Els. By striking Kon-El who is one of their most if not the most important member, he broke one of his sacred oaths.
It's part of a movie series there's a list online I made sure of that look up JL flash point pardox movie list this based of the 52 it's a more edgy DC has some darker themes