Coriolanus had never been the same after his short stint in the arena after going in to get the late Sejanus Plinth out. Having to kill that tribute. After the first kill, it only got easier and easier to kill. Even after he married you and got named President of Panem, his favored method was poison.

He was not the same at times loving person he had been before the arena. He was more ruthless. He didn't love freely. Not after what occured with Lucy Gray Baird.