Leonel had purposely left the various Patriarchs and Matriarchs of the families that Third Nova had made use of behind. It not only showed confidence in his story, but it also allowed the family Ancestors to double and triple check his story. In the end, they would have no method of refuting him. He had even left Third Nova's favorite little demoness behind as well.
But, therein lied a question. Why did he lie about Third Nova's death?
Really, he just wanted control. Lying about Third Nova's death was an opportunity he couldn't pass on because it would save him the trouble of dealing with other variables. So long as others thought that Third Nova was dead, they wouldn't ask to see him, or for him to be put on trial, and it would stop his branch and those that sympathized with him from finding a way to weasel him out of the situation.
But that obviously left another question. Why hadn't he actually killed Third Nova?
That answer was more complicated.