When Aqua fights Ventus with Vanitas in control, how did this happen? What is she fighting? In Ventus's story he fights with Vanitas in the dive to the heart. Was that fight the fight which determined who would be in control after combining their beings? If that's the case then during this battle for control, is it that Vanitas has the upper hand and therefore gets to control the body, making it so Aqua has to fight him while their hearts fight for power?