He had no remorse at all for taking the lives of those people. Years of isolation rendered him cold and apathetic to taking lives. He killed an entire Justice League before without giving it so much as a second thought. Taking lives had almost become second nature to him.
Prime flew backwards when the fist connected with his jaw. He flew into the top floor of an office building like a rocket. The entire building shook as he landed in it. Luckily for this particular building, the people on the floor were out to lunch. He pushed the wreckage off of himself and flew out of the building.
"I thought you would be stronger than that, Kara!" He yelled as he flew at her. He would show her pathetic. He egged her into throwing the first punch, but she was definitely going to pay for throwing it. He threw a high speed punch at her face. He'd hold back on his full strength just like he did with Conner.