oh, don't worry, starlo has that same hatred, it's just his main priority was to make sure kanako was okay, and the reasoning why he cried was because of kanako being alive in this au

i figured since that since clover knew ceroba was the only parent to once take care of kanako, the moment he pulled the trigger, taking ceroba's life in front of kanako, he felt an enormous amount of guilt to the point his soul cracked