Someone who is old, and wants to no longer be in charge, but he has a stubborn belief that only he can be the man who can steer the Ship that is Konoha. He is a kind, and ruthless in equal measure, but age has given him wisdom that he did not have in youth.
And he hates himself for not having that wisdom when he was a young man.
Belives only four people can take up the hat and allow him to live in peace. One is a bit on the evil side and to goody with Danzo to reasonably trust not to start another war, the second doesn't want it because he's wandering the earth writing porn, the third is a violent drunk who lost everything... and the fourth is the youngest among them who finally took the hat.