So Volibear is a juggernaut champion
But his ult has AP scaling?
He builds Titanic Hydra most games in top lane to split push, but the problem is his ult deals no extra damage for the items he builds. You can only rely on the base damage the ultimate provides.
Change his ult scaling from AP to AD then he will be a good pick in the top lane since his ult is the majority of his damage in a 1v1 split push scenario.