Madhouse

"She accused me of being ungrateful. She truly believed I would live as her son and ignore the mother who had brought me nothing but pain...I would have, I truly could have but then she crossed the line. I left her and waited for her to try to stop me, left myself completely open and waited..."

The Emperor actually never planned to bring Prime minister Zhao's crimes to light, that would have had too big of an impact on the Court, not to mention dragged half the ministers into the mess. It would have created quite the chaos.

All he wanted was to push her into trying to kill him so he would have an excuse to drag her down. But in the end, she refused to take the bait he dangled. She would not gamble. He had an army right outside the capital and could have handled any civil unrest with sheer force if he was pushed into it.