The fight. Hanzo remembered it. He had replayed it over and over in his mind to see find every mistake he made and if he could've known his brother was his attacker. His conclusion was no. He only knew when he summoned the dragon. There was no one but a Shimada who could. There were plenty of chances Hanzo had to kill his brother again had he not been distracted by memories of the first fight.

"We could if it wasn't a nest of assassins all out kill us." He paused for a moment. "Kill me."

The Shimada Clan thought Genji was dead. They knew Hanzo was alive and killing them. Every time he returned to Japan he was risking his life. They very badly wanted him dead. Hanzo simply killed them first.

"You could return safely and bring your master to show him. I imagine he would like to see where you came from." Hanzo would not go because to go he would put Genji at risk and he did not want that.

The last thing he wanted was to see his brother die again. Hanzo would not survive being responsible for it twice. He could only carry so much guilt and have so much blood on his hands before he snapped.