I wanted to just toss the coward like a rag doll with maybe a few broken or fractured bones. But I realized two things. How many other mutants has this trigger happy coward shot in the back? I know that look in his eye, he's definitely assaulted people who've tried to defend mutants. Calling other humans traitors just because they have a heart. 

No matter how much I could have scared him, he wouldn't have changed.  He would have still pulled the trigger in the past. So I wanted to wipe him out. To end him.

The other reason is because it just felt good. It put a smile on my face.