It Was Me, Dio! - Such deep questions...

What if we were to take Dio and swap his head with another person, say Jonathan, the who would Dio? You could say that is would to where Dio's brain is and thus that is Dio, but then what part does the body play? Jonathan's head would a the majority of what we call Dio, If Dio attached to Jonathan's body were to have a child would that child be Jonathan's or Dio's? Dio is the one who conceived the child however Jonathan's genetic material would be used to create said child