One of the saddest parts during the umbara arc was when kix was trying to save some of the clone troopers and Rex had to tell him to stop and to leave them. Like his body language and everything…he just looked so hopeless. I don’t agree with what he said to Rex afterwards but i can only imagine how useless he felt. He was told not to do the one thing he was meant to do. And like it wasn’t even just that, those were his brothers dying and he was told not to save them. He had to watch them die at massive rates and could do nothing.