Ignorance Is A Weakness.

The past can't be changed but the future is variable and full of possibilities. He can only use the information he got from causality to make decisions in the present. He is informed about the past but largely ignorant of the future. As for those who use fate, they know the implications of their actions despite being ignorant of the past. But have to anticipate every outcome and prepare for them. Some of their actions don't make sense in the present. But they will become obvious in the future. 

The first sage is cunning and so are those with his bloodline. They can't be trusted one bit and you can always be sure of one scheme or more from them. Whatever they do has to have an underlying meaning. Giving up her position and asking for him to kill her with the boost from his title don't make sense to him. But it must have some meaning that he doesn't know about.

'What is her aim?' he asked himself as he walked to the zeroth ring.