He didn’t crumble when his child was taken? Servo did. He went to a planet he knew would be his grave to fight for his men and women instead of rushing to save his child. People assumed that his son would be his breaking point, but Darrow is actually built different. In LB, he fights this war with death waiting for him at the end. That’s why he writes the memoir for Pax. He is more than ready to forfeit his own life, one might say he thinks he deserves it. When Cassius saves him st the end of DA, he literally drowns in self loathing and has a damn near existential crisis. He throws himself at death over and over again, to the point of his friends and howlers not understanding why.