Psychopathic badassery. He was a bit “troubled” before the war; imagine what he was like after...
I read about that as well. Serious PTSD. Insomnia, terrible dreams, vomiting, emotional problems (swings), etc.
Later on he tried to help Korean and Vietnam war Vets with PTSD...then called “battle fatigue”. Unfortunately it said he died in a plane crash when he was only 45.