If he can work out his mental problems and add a little muscle he would be amazing. Remember, Barcelona really wanted him, Man City really wanted him and he was really good for half a season with Conte.
He is still very young for a CB so I would love for our future CB's to be Tomori, Christensen and Aké/Rudiger. Unfortunately, I don't think we can have Zouma as a starter if he doesn't improve his ball playing skills.