sentences:  Meanwhile, Ventus is forced to fuse with Vanitas to create the χ-blade.Aqua and Mickey fight with the possessed Ventus and destroy the χ-blade, while Ventus engages and defeats Vanitas in a metaphysical battle within his own mind, losing his heart and falling into a catatonic state as a result.After learning of Ventus's condition from Yen Sid, Aqua brings his body to the Land of Departure, which she transforms into Castle Oblivion to ensure Ventus will not be disturbed.