It is a deal breaker to me because of "He does not fit in the company culture that we want to build". The company culture is not something you artificially bui

It is a deal breaker to me because of "He does not fit in the company culture that we want to build". The company culture is not something you artificially build for an abstract entity called "company". The culture of your company === the culture of the people that form your company. There is no workaround if he joins your company. And as he is more senior, famous and all, the influence on the company will be maybe larger than yours. You will get job candidates that get to know the company because of this person.