Venus is described as shy, and is very awkward. People seem to feel uncomfortable when he gives his nervous smile, as most are described to want to punch him in the face. He gets distracted very easily, usually pointing out lights that no one else can see. 

Although Venus is biologically male, it is revealed that his 'demon' is that deep down, he is a she. If... that makes sense. So, although she is male, her voice should have a bit of a feminine touch to it. (basically shes a trans girl! and she transitions in game uwu)